Did this in Colors for the NDS.
Color, briefly, is a homebrew program for the Nintendo DS. Its interface is extremely simple but its use of the pressure-sensitive touch screen makes everything intuitive.
I'm really more of an sketcher and illustrator rather than a painter. Color has always been my weak point, as I tend to see lines and structures. But Colors for NDS has been a great introduction into painting, and now I'm beginning to see in terms of lines and shades.
My work still doesn't hold a candle to some in the Colors gallery, though; but I'm sufficiently inspired to want to keep working.