Colourising is a great technique if you want to change an image’s colour after you’ve used a certain tutorial, or just want to make a graphic or photo co-ordinated with the rest of your layout or design.
Open up the image you want to colourise, and go to Image > Adjustments > Hue/Saturation.
You can then adjust the hue, saturation and lightness sliders to alter the colours of your image. Depending on what you’re altering, you may not need to check the Colorizing box to change the colour.
Once you’re happy, click OK to transform your image.