Just started to mess around with paint.net. I've put a request in for a repaint of this aircraft (no harm in asking!), but in the meantime I'm trying to have a go myself.
Here's one of the existing schemes which I decided to use as a base - Nice wave of colour.
I decided to change the white parts and get rid of the company logos. I use DXTBmp to open the texture then send the image to paint.net to play with it. I guess I got lucky with the grey - just filled in the white with a paintbucket! Didn't work with the forward wings though - that texture includes other components which I didn't want re-colouring. That's the hard part I guess, going around the texture placing random splashes of bright colour just to see where it shows on the model.
Whilst the green is nice and glossy I want to change it to another colour. From the tutorials I've seen I think it's just like using a colouring book - I can't select the green on it's own I just have to paint up to the line and don't go over it LOL!
Early days...