Hi there and welcome
Ok this is one way of doing that.
First copy your background image.Drag your background images layer down onto the little icon which looks like a little page,its at the bottom of your layer palette.Now click back on your copy and click on the little icon at the top of your layer palette as shown in the image.Next go to the top of your screen and the IMAGE > ADJUST MENU > select HUE AND SAT,and click ok.With the hue and sat window open browse to your right and click the COLORIZE box,now move the HUE slider and you can make your image any hue you like,blue green etc