Anodised keys
My view was then simply cut them from a coloured or patterned key, but not all keys can be.
So I then came up with the idea to anodise them, but this process is expensive and can only be applied to aluminium keys.
It's about £60-£80 for one process, but if each key is to be a different colour then it isn't economical. I checked online and there are a number of caustic chemical used, with varying results, so I'd prefer to get it done commercially.
Any ideas on anodising, or perhaps electroplating ?