Colour is a guess, and that is fine
The model infers plausible colours from context: skin, sky, fabric, foliage. It is an interpretation of the scene, not a record of it.
Say what you know
If you remember the dress was green, write it. Named colours override the model's guess and make family photos feel right.
Restore first, colorize second
Damage and grain confuse colour inference. Run the restoration pass first, then colorize the cleaned image.
FAQ
Will the colours be accurate?
Plausible rather than accurate. Name colours you know to correct it.
Does it handle faces well?
Skin tones are the strongest part of the model. Judge on a close crop.
Should I keep the original?
Always. Colorization creates a new interpretation and does not replace the archive scan.
Can it colorize a black and white photo?
That is exactly what it does. Upload the scan and pick a colour mood, or name colours you remember.