Avoid using red in dim light. Each color alters our perception of other colors. A pure color shifts adjacent colors toward their complements. Use complementary colors to enhance contrast. Chromostereopsis Blue objects come into focus nearer the lens than red objects.
Red objects appear closer than blue ones.
Use to enhance depth perception. Use blue as background. The eye sees a dot of white as a white point fringed with color. This distortion is especially severe at the blue end of the spectrum. Avoid pure blue for small objects or text.