NotifyIcon Size and Color requirements

[John]

I'm a coder not an icon designer. However, I've been tasked with getting a
NotifyIcon to look better in the task tray. I just can't seem to do it
though. Does anybody know what the optimal requirements are for the icon
that is displayed in the task tray? What size? How many colors? Every icon I
try looks bad. I've tried sizes of 16x16, 20x20, 24x24, 32x32, 48x48, and
128x128. I've tried 16, 256, and true color. But either the icon is a dither
bomb, or it looks stretched.

Any help is appreciated,
John