“The color is different” is actually a very ambiguous statement

In coating operations, customers sometimes make comments such as the following.

“The color is different.”
“It looks deeper than last time.”
“It feels a little paler.”
“It has a different appearance from the standard panel.”
“It somehow looks dull.”
“The color is close, but it looks different.”

When comments like these are received, the shop floor tends to immediately suspect the coating material batch or color matching.

However, “the color is different” has a very broad meaning in practice.

The actual difference may be in hue.
It may be in lightness.
It may be in chroma.
It may be in gloss.
It may be in surface texture.
It may be in lighting conditions.
It may be an effect of film thickness or the underlying surface.

Simply accepting the words “the color is different” makes it difficult to move on to root-cause analysis.

The first step in responding to a color difference is not apologizing or immediately contacting the coating manufacturer.

The first step is
to identify exactly what looks different and how.

Color can be described through three elements

There are useful basics for describing color.

These are the following three elements.

1. Hue
2. Lightness
3. Chroma

Simply considering these three elements separately makes discussions of color differences much easier to organize.

1. Hue: Differences in the type of color

Hue is the difference in color type, such as red, yellow, green, blue or purple.

For example, even within red, the following differences exist.

• Yellowish red
• Bluish red
• Red close to orange
• Red close to purple

Similarly, gray can have the following differences.

• Bluish gray
• Yellowish gray
• Reddish gray
• Greenish gray

When a customer says the color is different, the actual difference may be in hue.

For example, it may be slightly more yellow than the standard panel.
Slightly more blue.
Slightly more red.
These are hue differences.

Describing this simply as “deeper” or “paler” can lead to a correction in the wrong direction.

Questions such as the following are useful for checking a hue difference.

• Does it look more yellow than the standard panel?
• Does it look more blue?
• Does it look more red?
• Does it look greenish?
• In which direction does the hue seem to differ?

Checking hue makes it easier to consider color matching, film thickness and the influence of the underlying surface.

2. Lightness: Differences in brightness

Lightness is the brightness of a color.

Simply put, a color looks lighter as it approaches white and darker as it approaches black.

When a customer says “deeper,” they may actually mean that it looks darker.
Conversely, “paler” may actually mean that it looks lighter.

However, care is needed here.

The words “deep” and “pale” mean different things to different people.

One person may use “deep” to mean dark.
Another may use it to mean vivid.
Someone else may use it to mean that the film looks thick.

When a customer says “deeper” or “paler,” it is therefore necessary to check whether they mean a difference in lightness, rather than simply repeating those words.

Ask questions such as the following.

• Does it look lighter than the standard panel?
• Does it look darker than the standard panel?
• Does it look whitish?
• Does it look blackish?
• Could the way light falls on it be making it look lighter?

Differences in lightness are readily affected by film thickness, underlying color, gloss and lighting conditions.

3. Chroma: Differences in vividness

Chroma describes how vivid a color is.

Vivid red versus dull red.
Vivid blue versus grayish blue.
These are differences in chroma.

When a customer says the color looks dull, its chroma may appear low.
Conversely, if it seems too striking or too intense, its chroma may appear high.

Chroma differences are affected by color matching, pigments, film thickness, the underlying surface, gloss, surface texture and other factors.

For example, excessive mixing of coating materials can make a color look muddy.
The underlying surface can make it appear less vivid.
Low gloss can also make a color look slightly dull.

Questions such as the following are useful for checking chroma.

• Does it look more vivid than the standard panel?
• Does it look duller than the standard panel?
• Does it look grayish?
• Does the color seem weak?
• Does it seem too striking?

Checking chroma makes it easier to notice causes other than a simple hue difference.

Do not confuse gloss differences with color differences

Gloss is particularly important when responding to a color difference.

Even with the same color, a difference in gloss can make it look like a different color.

A glossy surface strongly reflects light.
As a result, it may look lighter or appear to have greater depth.

A matte surface scatters light.
As a result, it may look subdued, whitish or dull.

In other words, when a customer says the color is different, the actual difference may be in gloss.

Correcting the color match without checking this can lead in the wrong direction.

For example, the color may match but look lighter because the gloss is higher.
If the color is darkened in this case, it will then be wrong once the gloss is matched.

Check the following points.

• Is gloss specified?
• Is the finish gloss, semi-gloss or matte?
• Do the standard panel and production product have the same gloss?
• Is a gloss meter used to check it?
• Is the gloss uneven?
• Could a difference in surface texture be appearing as a gloss difference?
• Has a difference in drying conditions changed the gloss?

Color and gloss need to be considered together when evaluating appearance quality.

Surface texture also affects color appearance

The surface condition of the coating film also affects how the color looks.

Even with the same color and gloss, a different surface texture changes the impression.

For example, a smooth surface reflects light consistently.
A rough surface, on the other hand, scatters light irregularly and can make the color look whitish or dull.

Orange peel, poor surface texture, dirt inclusions, contamination or roughness can make the overall appearance look different even if the color itself is unchanged.

Check the following items.

• Does the surface texture match the standard panel?
• Is there orange peel?
• Are there dirt inclusions or contamination?
• Is there roughness?
• Is film smoothness the same?
• Are repair marks visible?
• Are sanding marks left?

Appearance quality is judged through color, gloss and texture together.

“Deep” and “pale” alone do not convey the issue accurately to the shop floor

The words “deep” and “pale” are frequently used in coating operations.

However, these expressions alone leave the direction of improvement unclear.

When a color is described as deep, there are several possibilities.

• Low lightness
• High chroma
• Thick film
• High gloss
• Dark underlying surface
• Hue shifted toward red or blue
• Lighting makes it look dark

The same applies when a color is described as pale.

• High lightness
• Low chroma
• Thin film
• The underlying surface shows through
• Low gloss
• Whitish appearance
• Lighting makes it look light

Thus, “deep” and “pale” are convenient words but insufficient for quality improvement.

Shop-floor language needs to be as specific as possible.

For example, use descriptions such as the following.

• It looks darker than the standard panel
• It looks lighter than the standard panel
• It is more yellow than the standard panel
• It is more blue than the standard panel
• It is duller than the standard panel
• It has higher gloss than the standard panel
• It has lower gloss than the standard panel
• It looks whitish because the surface texture is rough

Such descriptions make discussions between sales, quality, the shop floor and the manufacturer much more accurate.

Questions to ask when handling a color-difference complaint

When a customer says the color is different, CoatureVietnam’s sales and quality personnel can organize the issue by asking the following questions.

1. Check the comparison reference

• Compared with what does it look different?
• The customer’s standard panel?
• The previous batch?
• The approved sample?
• An image or printed material?

2. Check hue

• Is the hue different?
• Does it look more yellow?
• Does it look more blue?
• Does it look more red?
• Does it look greenish?

3. Check lightness

• Does it look light?
• Does it look dark?
• Does it look whitish?
• Does it look blackish?

4. Check chroma

• Does it look vivid?
• Does it look dull?
• Does it look grayish?
• Does the color look weak?

5. Check gloss

• Does the gloss look high?
• Does the gloss look low?
• Is the gloss uneven?
• Does it have the same gloss specification as the standard panel?

6. Check surface condition

• Does the texture look rough?
• Are there dirt inclusions or contamination?
• Are there repair marks?
• Is there roughness?

7. Check the viewing environment

• Under which lighting was it checked?
• Were the standard panel and product viewed in the same place?
• Were they viewed at the same angle?
• Were they viewed against the same background?
• Was it natural light or factory lighting?

8. Check process conditions

• Is film thickness within the standard range?
• Are the underlying surface conditions the same?
• Is the thinning ratio the same?
• Are drying conditions the same?
• Is the coating material batch the same?
• Was stirring sufficient?

These checks turn the ambiguous comment “the color is different” into a concrete root-cause investigation.

Causes of color differences through 4M + Management

CoatureVietnam also uses 4M + Management to investigate color differences.

Material: Materials

Items to check from the material perspective.

• Coating material batch
• Color-matching batch
• Pigment dispersion
• Stirring condition
• Thinning ratio
• Thinner used
• Hardener mixing ratio
• Primer
• Underlying color
• Standard panel
• Acceptance-limit sample

Possible material-related causes include differences between coating batches, color-matching differences, insufficient stirring and the influence of the underlying surface.

Method: Methods

Items to check from the method perspective.

• Film thickness
• Number of coats
• Spray distance
• Gun travel speed
• Coating delivery rate
• Drying conditions
• Baking conditions
• Repair method
• Inspection method
• Color evaluation conditions

Even with the same coating material, different film thicknesses or drying conditions can change color and gloss.

Machine: Equipment

Items to check from the equipment perspective.

• Spray gun
• Coating supply equipment
• Stirrer
• Drying oven
• Inspection lighting
• Colorimeter
• Gloss meter
• Film thickness gauge
• Inspection bench
• Booth environment

Unstable equipment conditions change film thickness, gloss, texture and color appearance.

Man: People

Items to check concerning people.

• Differences in coating technique between operators
• Differences in judgments between inspectors
• Judgment by the customer’s personnel
• Information gathered by sales personnel
• Analytical ability of quality personnel
• Operator training

Differences in people’s perception cannot be ignored when responding to color differences.
Criteria and evaluation conditions therefore need to be aligned.

Management: Management

Items to check from the management perspective.

• Standard panel management
• Acceptance-limit sample management
• Records of color measurement values
• Gloss criterion management
• Customer approval history
• Coating condition records
• Color-difference history
• Alignment between customer and internal criteria
• Inspection SOP
• Training records

Color management needs to be considered as ongoing management, rather than isolated responses.

Misunderstandings commonly encountered in Vietnamese factories

Quality issues in Vietnamese factories are often handled in multilingual, multicultural environments.

Nuances can differ when color is described in Japanese, Vietnamese and English.

For example, the following expressions may be used.

• Deep
• Pale
• Light
• Dark
• Dull
• Vivid
• Yellowish
• Bluish
• Glossy
• Matte
• Whitish
• Blackish

Even after translation, these words do not necessarily convey exactly the same impression.

When responding to color differences, it is therefore important to combine words with physical samples, photographs, color measurement values and acceptance-limit samples.

When working with Japanese customers in particular, the following forms of standardization are useful.

• A sample approved in Japan
• An identical standard panel for the Vietnamese shop floor
• Acceptance-limit samples shared with the customer
• Shared color measurement values
• A rule against judging by photographs alone
• Documented inspection conditions

Color discussions can diverge when they rely only on words.
Sharing physical references and conditions is important.

The ability sales personnel need when responding to color differences

Responding to color differences is not only the job of quality personnel.
Sales personnel also have an important role.

Sales is often the first team to hear the customer’s concern.

If sales reports only “the customer says the color is different,” information will be insufficient.
Quality and technical teams cannot begin root-cause analysis.

On the other hand, the response changes substantially if sales gathers the following information at the outset.

• Different compared with what?
• Which areas are different?
• Under which lighting was it viewed?
• Is the difference in hue, lightness, chroma or gloss?
• Was it viewed under the same conditions as the standard panel?
• Is information on film thickness or drying conditions available?
• Has the customer measured the color?

This information improves the quality of the initial response.

Sales personnel do not need to become color specialists.
However, they need the ability to break down “the color is different” when gathering information.

That is the value of sales personnel who understand the coating process.

How CoatureVietnam can help

CoatureVietnam does not treat color differences as simply a coating material problem.

We organize the customer’s comments, examine causes through 4M + Management and connect them to recurrence prevention.

We can support the following activities.

• Initial organization of color-difference complaints
• Structured questions on hue, lightness, chroma and gloss
• Support for using standard panels and acceptance-limit samples
• Clarifying color measurement conditions
• Checking film thickness, gloss and underlying surface conditions
• Checking coating conditions
• Standardizing inspection conditions
• Preparing question lists for sales personnel
• Appearance judgment training for quality personnel
• Preparing SOPs to prevent recurrence of color differences
• Aligning customer and internal criteria

CoatureVietnam aims for more than simply matching color.
We aim to establish conditions in which everyone involved can organize causes in a shared language when a color difference occurs.

Conclusion

In practice, “the color is different” is a very ambiguous statement.

The actual difference may be in one of the following.

• Hue
• Lightness
• Chroma
• Gloss
• Surface texture
• Film thickness
• Underlying surface
• Light source conditions
• Standard panel
• Inspection conditions

Handling color differences correctly requires these differences to be identified and checked separately.

Root-cause analysis cannot progress with subjective descriptions such as “deep,” “pale” or “somehow different” alone.
Considering hue, lightness, chroma and gloss separately helps organize discussions among sales, quality, the shop floor and the customer.

The following perspective is important.

Color differences are difficult to resolve through subjective discussion.
Checking hue, lightness, chroma and gloss separately makes root-cause analysis and customer explanations easier.