Here's a partial coloured copy of Arnie's & a bit more colour in the second pic.
I'm just new to this sort of thing. so i'm not the best

The first 2 were done in GNU/Gimp and the 3rd done in Photoshop using wine as an emulator all in Linux.
Gimp is a free opensource alternative to photoshop both for windows & Unix/Linux.
The only difference that i could note is Gimp does have a lasso but it's not magnetic as in photoshop, so you have to have a pretty steady hand.