Rainbow Effect

Choose any image, and open it in adobe. I used this one.

Go to layer>>layer style>>gradient overlay. Use the settings below.


Click on the bar beside Gradient. In the new window that comes up, you should see a large gradient bar close to the bottom. There are two arrows, or "stops", that point to the gradient bar from the bottom and the top. On the left, click on the bottom stop. Underneath the gradient bar, you will have the option to change the colour of the gradient bar. Change the colour to whatever you want, and do the same for the right-bottom colour stop. Click OK on both windows.


Now you're done! Look at the great results: