A painter mixed equal amounts of red and blue, but the violet appeared muddier than expected. What is the most likely reason?

Correct answer: The pigments had opposing colour biases or contamination

In an ideal traditional mixing exercise, red and blue can produce violet. However, real pigments are not perfectly pure: a red may lean toward yellow and a blue may contain a greenish or other unwanted bias. Such opposing undertones, or contamination from an unclean brush or palette, introduce extra wavelengths and reduce saturation, making the violet muddy. A large palette or white surface does not normally cause this result.