What color do blue green and red make?

when you use equal of each color going from 0 to 255

red = 0 green = 0 blue = 0 makes the color black

red = 100 green = 100 blue = 100 makes the color: dark gray

red = 255 green = 255 blue is 255 makes the colour white.

So evertime you increase the value from 0 towards 255

you will go from black to grey tints to white in the end.