How to create an easy gradient in MS Paint

First off, you need to work out your START COLOR and your END COLOR (i.e. the top and bottom of the gradient). Also, work out the HEIGHT which your gradient will be.

Make the canvas as high as you want the gradient to be, and then start off by placing a line of your top color at the top, and your bottom color at the bottom (simple!).

The slightly difficult bit comes now. Find the differences in the RGB numbers of each separate R, G and B between the top and bottom. For each row, determine the fraction of the image from the top which it is, and then subtract the product of this fraction and the difference you just worked out to the R, G and B sections of the top color. Confused? I apologise, here’s an example:

From RED to HALF-YELLOW (RGB 255, 0, 0 and RGB 128, 128, 0)

The height will be, say, 10.

Start off with the two straightforward lines, and then working from the top downwards:

The RED difference is 255 – 128 = 128. The GREEN difference is 0 – 128 = -128, and the BLUE difference is 0 – 0 = 0.
The first line is 1/9^th of the way down (because we start at 0/9^ths, this doesn’t have any color change ), so its RED color is 255 (same as the top) - (1/9 × 128) = 241 (to the nearest whole). Its GREEN color is 0 (same as top) – (1/9 × -128) = 14, and its BLUE color is 0 – (1/9 × 0) = 0. The RGB color for this line is therefore 241, 14, 0. If you keep this sequence going, then the rest is simple, merely
255, 0, 0
241, 14, 0
227, 28, 0
212, 43, 0
198, 57, 0
184, 71, 0
170, 85, 0
155, 100, 0
141, 114, 0
128, 128, 0

P.S. If you're confused, I have made a program to do it for you (plus other features): jupiter.walagata.com/w/design/ZDGrads.zip