RGB Color in Python: build palettes and fades in code

A color is a tuple of three integers, 0–255, for red, green, and blue. Because it's a tuple, you can pull out one channel by index — [0] is red:

red = (255, 0, 0)
teal = (0, 128, 128)
print("red:", red)
print("teal:", teal)
print("red channel of red:", red[0])

red: (255, 0, 0)
teal: (0, 128, 128)
red channel of red: 255

teal mixes equal green and blue. Once color is numbers in a tuple, you can inspect a channel — and, next, compute one.

Here's the key move: generate a color in a loop instead of hand-picking it. Each pass raises the red channel by a fixed step while green and blue stay put:

for i in range(8):
    red = 40 + i * 27
    print(i, "->", (red, 60, 200))

0 -> (40, 60, 200)
1 -> (67, 60, 200)
2 -> (94, 60, 200)
3 -> (121, 60, 200)
4 -> (148, 60, 200)
5 -> (175, 60, 200)
6 -> (202, 60, 200)
7 -> (229, 60, 200)

The red channel climbs 40, 67, 94 … in even steps while green and blue hold at 60 and 200. Paint each of those colors onto a star and the steady climb becomes a smooth fade.

Now render that computed fade. It's the exact 40 + i * 27 from the warm-up, feeding each color to a star across the row:

python

from art import Canvas, star

screen = Canvas.create()
Canvas.fill(screen)

for i in range(8):
    red = 40 + i * 27
    color = (red, 60, 200)
    star(screen, 60 + i * 55, 250, size=44, color=color)

Same numbers you printed above, now as pixels: the color slides predictably because the math does. Since color is just math, you can interpolate between any two colors, brighten by scaling all three, or map a data value to a hue.