The alternative forms RGBColor[{r, g, b}] and RGBColor[{r, g, b, a}] can also be used. »
Red, green and blue color intensities outside the range 0 to 1 will be clipped, as will opacities. »
On monochrome output devices, a gray level based on the average of the color intensities is used.
For 3D surfaces, explicit RGBColor directives define surface colors; the final shading depends on lighting and contributions from specularity and glow. »
Glow[RGBColor[...]] specifies color independent of lighting. »
In RGBColor[r, g, b, a], a is an "alpha channel" used to specify opacity.
RGBColor[r, g, b, a] is equivalent to {RGBColor[r, g, b], Opacity[a]}. »
If no opacity has been specified, RGBColor[r, g, b] is equivalent to RGBColor[r, g, b, 1].
Style[expr, RGBColor[...]] specifies that expr should be displayed with the specified color. »
EXAMPLES
Basic Examples 
Scope 