Q: I’m having trouble darkening and lightening tube colors. Any suggestions?
A: To get richer darks and lights, try using complementary
colors. Dulling the tube color with its complement, then applying the
pure color next to it, will suggest a light area just through the
difference in saturation. A touch of white for the highlight will
enhance the effect. If necessary, add a touch of black to the mixture
of complements to make it darker.