blue light, blue car?

@jonnythan Said

A blue light emits blue light*.

A blue car reflects only blue light*.

*or those colors of light that combine to make blue.

You seem to be asking about "additive" (light) versus "subtractive" (pigment) colors. A quick Google search will explain it all for you.

@Willi Said

is blue pigment blue?
or does it reflect as blue because it has no blue for blue to absorb with?

@jonnythan Said

Blue pigment reflects blue light and absorbs others. If you shine a red light on a blue-pigmented surface, it will look black because the red light has no blue for it to reflect.