Mac OS Classic's crayon color picker but for Mac OS X.
I know Mac OS X has a crayon picker already (now called "Pencils"), but I've always found it rather disappointing. I've always thought the Mac OS Classic crayon picker had a much better set of colors.
So here it is, back in all its glory.
Built on 10.6.8, tested on 10.6.8 (Snow Leopard) and 10.14.6 (Mojave).