Terminal color is represented by means of "color pairs". These are just numbers, from 0 to Color.Pairs - 1 (0 being the default for everything) that are associated to a foreground and to a background color and are used as attributes for characters on the screen.
Similarly, all colors - see the color constants in this class which represent the ANSI standard ones - are just numbers from 0 to Color.Colors - 1 which are, connected to RGB values.

The more important part, however, is that one has to stick to that number representation, especially for color pairs. You can fancily color one line of text with color pair 1 (which was previously defined by you) but as soon as you change the definition of color pair 1, the line mentioned above will change to that new definition! (BTW, you access a particular color pair through the array accessors of this class)

Having said above that 0 is the default color pair for everything, think of the Window class... It is true for it also. So, using the Window.Background and Window.Foreground properties affect exactly the same color pair that was set through Window.Attributes.Color, which, in turn, is 0 per default.

I hope, it was clarified that using color will take some extra thought...

This class is static.

This class acts like a read-only static array.

Constants

Black	The color Black
Blue	The color Blue
Cyan	The color Cyan
Green	The color Green
Magenta	The color Magenta
Red	The color Red
White	The color White
Yellow	The color Yellow

Static properties

Available	Returns if color is available.
CanChange	Returns if the color values can be changed.
Count	Returns the number of supported colors

Static methods

Set	Sets the Value of one of the colors to the provided red, green, blue combination