Which traditional primary colour generally has the darkest value?

Correct answer: Blue

Value is the lightness or darkness of a colour when compared with others. In the traditional red-yellow-blue set, blue is generally perceived as having the darkest value, so option B is correct. Yellow is normally the lightest, while red tends to occupy a middle position. Orange is a secondary colour produced by mixing red and yellow, so it is not a traditional primary colour in this question.