Bgcolor in all squares is "#000066" (dark blue) and gradcolor is "#00cccc" (turquoise). The angles used are specified beneath each square. I have started with:
The default, 0 and 180 angles, which arrange the colors from top to bottom, giving a horizontal gradient;
Then the 90, minus 90 and the 270 angles which arrange the colors from left to right, producing a vertical gradient;
Next come the angles 30, 45, 60, and 90 which are accompanied by their minus and related angles greater than 90 degrees, as we move around the clock face, starting with 3 as our zero point.
The angles less than 90 degrees emphasize the gradcolor. Those greater than 90 degrees give equal emphasis to both colors. I have not used minuses with angles greater than 90 degrees.
default
0
180
90
-90
270
30
-30
150
210
45
-45
135
225
60
-60
120
240
SMAN'S GRADANGLE CHART
jpg by Tatiana
For a different perspective about gradangles, check out Gnubee's Gradangles Recipe. Gnubee puts the 0 at #6 on the clock; while I put the 0 at #3.