When Painting a character on a background

This is just the Briefest of overviews on Light and Color as applied to a simple character design.
I highly encourage a good painting class to study these essential concepts and in the mean time recommend the two best books out there on the subject:

Carlson's Guide to Landscape Painting - John F. Carlson
Color and Light - a guide for the realist painter - James Gurney

So when working on your next assignment, which is a character in a simple background, or when doing any character in any environment, here are some of the main things to think about - not necessarily in this order:

Value
Lighting,
Mood
Color
Tone

Value

first off – decide how you are going to make your character stand out from the background. White on grey, grey on white, black on white, white on black etc. Each will have a slightly different effect which may or may not matter to how your character is best portrayed. Pick one though and be concious of that as you add color.

Lighting – This should probably go with the value section, but be thinking how your character is best lit – if lit at all. Is if perfectly flat? Some shading? “form” shading? Shading with a specific light Source?

Directional lighting – different directions convey different moods – Dramatic low lighting casts strange frightening shadows. High lighting can look natural – like daylight. Soft diffused light, hard harsh light,  Strong light from directly above, Light in front of the figure (Light figure on dark background), light behind the figure (dark character on light background)

Mood - 

Also similar to what was said in lighting, first know your character or the story you are trying to tell (remember, that even one simple painting can tell its own story).  The overall Mood of the piece is influenced by the above principles as well as color.  know the mood you want - that will guide you in your decision making

Color

COLOR IS VALUE!!!!

Whatever you do – don't lose your value while you add color!!!!!!

 - be aware of the emotions behind different colors as well as different pallats (complementary, Gamut, Tertiary etc.)

TONE

" The artist feels the almost omnipresent light saturating all tones, bringing them into unity, no matter what differences may exist in the "local color of his masses."

The light's color cast diffuses itself over and into the colors of such an object and thereby establishes a kind of unity or "tone" over the whole.

COLOR IS VALUE!!!!

understand this and you have the key in your hand

We do not paint "exact" colors; we paint them as they impress us, differently each day.  (thus, painting a yellow shirt with yellow with yellow highlights and yellow shadows would prove less effective than an artistic perception)

It is the Prerogative of the artist to really see light and color, especially in shadows.  to the average layman, light and color do not eist to such exalted degrees.

CREATING SPACE

"when men speak of creating "space" in a picture it means only that they have understood their light pretty well. a space in a picture is composed of light. our eyes do not see black void.

(blackness thus would denote "non-space" - imagins a small enclosed area, such as a cupboard or drawer.)

 - AERIAL PERSPECTIVE - The expression of space by changes and gradations of color distinctness and hue.

All colors become cooler as they recede from the eye, except white. - the addition of white to any of these colos or mixtures tend to cool them.

bright white objects behave differently from dark objects. Rather than growing cooler or grayer with distnace, they become warmer in color. - gurney

It is the yellow that fades out of a landscape as it recedes from the foreground - as the yellow fades out, the violets and blues seem to increase in intensity. The yellow fades int practical nothingess long before the other tow primary colors (red, then blue)

All things become lighter in value as they recede from the eye