Colour Difference Formulae Questions and Answers

Answer: C

Both are true and the reason gives the basis, and a fashion garment differs from a car body panel. The formula and the number must both be agreed. A tolerance is a commercial agreement. Vision alone does not settle the number.

Answer: D

Correct answer: a large difference in one component may be masked by the total

The total combines the three components in quadrature, so a batch that is well off in hue but close in lightness and chroma can return a modest total and pass. Since hue is the least tolerated component, that is exactly the failure most likely to be objected to. Component tolerances alongside the total are what prevent it.

Answer: A

Both are true and the reason gives the reason, and the total conceals the direction. A hue tolerance is commonly the tightest of the three. Hue errors are the least readily tolerated. A hue tolerance is usually the tightest specified.

Answer: B

The first two are correct and are why both are usually specified. The third overlooks the masking that a single combined figure permits. Components constrain each attribute separately. A total conceals the direction of the error.

Answer: C

Inter-instrument agreement is typically better for differences than for absolute values. Measuring standard and batch on the same instrument removes much of the disagreement. Systematic errors largely cancel in a difference.

Answer: D

Correct answer: Both A and R are true, and R is the correct explanation of A

Both are true and the reason gives the mechanism. Every instrument has small systematic departures in its wavelength scale and photometric response, and those affect the standard and the batch almost identically. Taking the difference cancels most of them, which is why inter-instrument agreement is far better on differences than on absolute values.

Answer: A

Correct answer: 1 and 2 only

Statements 1 and 2 go together and are the reason a supply chain can work with different instruments at each end. Statement 3 is not true of any two real instruments - absolute values differ by an amount that matters, which is why standards and batches should be measured on the same machine wherever possible.

Answer: B

Metameric pairs match under one illuminant and separate under another. Calculating the difference under several illuminants exposes this directly. A metameric pair separates when the light changes. One illuminant would conceal the failure.

Answer: C

Correct answer: Both A and R are true, and R is the correct explanation of A

Both are true and the reason gives the mechanism. Where the samples differ spectrally, the illuminant decides whether they integrate to the same tristimulus values. One illuminant therefore tests only one condition, and computing the difference under a second exposes the metameric failure that the first concealed.

Answer: D

The pair is first corrected to match exactly under the reference illuminant. Any residual difference under the test illuminant is the index. The reference match is established first. Residual difference under the test light follows.