Step 1: Start off by opening Photoshop, and than opened your desired image. File -> Open.
Step 2: Now go up to Image -> Adjustments -> Hue / Saturation
or you can just hit (CTRL + Alt + U) on your keyboard.
Step 3: Now a box should popup like below. Make sure the "Colorize" box is checked, and you can now mess with the
values. Saturation is how strong the color will be, Hue is the actual color, and Lightness is how light or dark the color will be.
Once you select what you like, hit OK, and your done!
Step 4: And heres the outcome!