What is the usual result of mixing blue and orange poster colours?

Correct answer: Neutral or muted

Blue and orange are complementary colours. In subtractive pigment mixing, complementary pigments tend to reduce one another’s saturation, so the mixture commonly becomes neutral, greyish, brownish, or muted; option A is correct. The precise colour depends on the paint pigments and their proportions. A bright green would require suitable blue and yellow, while pure red or light yellow cannot be predicted from this complementary mixture.