How to colourise a black and white photo

Old black and white photos can be colourised by hand with Colourise with Hints. In Paint by Zaweba you add a hints layer (Image > New Colour Hints Layer), scribble a few strokes of colour onto the greyscale picture, then run Image > Colourise with Hints. The colours are spread across the photo by optimisation, following the shapes in the picture, and the result lands on a new layer.

This is a guided method. You decide every colour, and the software works out where each one should go. It's quite different from automatic colourisers that guess colours for you, and it suits family photos where you know a dress was blue or a front door was red.

What you need

A scan of the photo, as sharp and clean as you can get it, and Paint by Zaweba on Windows. It works offline, so precious family pictures never leave your PC. If the scan has dust or scratches, fix those first, because the colour spreading follows edges and a scratch can act as a false edge.

Step by step

Open the photo. If it's a colour scan of a black and white print, it may have a brown or blue tint; that's fine, but you'll get cleaner results starting from neutral grey.

Choose Image > New Colour Hints Layer. This gives you a layer to scribble on, kept apart from the photo.

Pick a colour and draw a short stroke inside each region: a line across the sky, a dab on each face, a stroke down a coat, a squiggle on the grass. You don't need to fill areas in. Small, confident strokes in the middle of each region are what the method wants.

Run Image > Colourise with Hints. The hints spread outwards, stopping where the picture's tones change, and a new colour layer appears above the photo.

Look at the result and add more hints where colour leaked or didn't reach. A face that went partly green from a nearby hedge needs another skin stroke closer to the edge. Run it again. Two or three rounds is normal.

Choosing believable colours

Real colours in old photos were usually softer than we expect. Pick muted versions of each colour rather than bright ones. Skin especially needs care: choose a gentle warm tone and give lips and cheeks a slightly different hint. Sample colours from a real modern photo with similar lighting if you are unsure.

Remember the brightness is already in the picture. A hint only sets the colour, so a dark grey coat painted with a pale blue hint still comes out a dark blue.

Getting a good result

Lower the colour layer's opacity a touch at the end. Slightly less saturation nearly always looks more natural. Check the edges between regions at full size, and if a colour has crept over, either add a hint or paint on a mask on the colour layer.

Keep the hints layer. If a relative remembers the car was green, not grey, you can change one stroke and run it again instead of starting over.

What else helps

Paint by Zaweba's retouching tools are useful before you start: Dust Spot Finder and the Scratch Remover clean up a damaged print so the colours have clean edges to follow. Afterwards, an adjustment layer can warm or cool the whole picture so it feels of its time. Colourising is a patient job, but with hints doing the heavy lifting it is quicker than painting every region by hand.