If like me you cannot afford Photoshop, Pixlr is a good alternative. However it can be difficult to fully utilise the free resource especially with the limited amour of tutorials there are. So here is how you do a simple colour replace.
For this tutorial I will be using this photo of the lovely Jude Law
Ok so once you have uploaded your photo you will come to this screen
we will start with something easy changing his green background
First click on the pipette tool it looks like this
click on the background using this tool and this will happen
Now click on the small box of colour (in this case the green) and choose a new colour.
I have chosen a pink!
Now click on the colour replace tool, it looks like this.
Now go up to the top of the screen and go on the brush menu as pictured
As this is a vast space I have chosen a bigger brush the 30 on the second row. feel free to experiment at this point.
now start colouring in your chosen section!
see not too tricky was it!