Quick photoshop job

Hi, I need a higher res version of the attached image. I have a tif file of three of the colours but I don't have the last two in it. What I need is the last two colours (the green and grey) to be added to the gif by recolouring one of the four existing colours. Hope this makes sense. This is a very small job but if it is done well, it will lead to more work in the future. Thanks