First step to success is to get a black and white photo, then open it in Photoshop. Create a new layer (name it lips) and change the mode to ‘’colour’’. Then get the brush, choose the colour to red and paint the lips.
The next step is to create a new layer (name it skin), then get the brush and choose the colour of the skin you want. Create a layer for hair as well.
Then you can just play around by adding layers for each part of the face you want to colour.