With the currently planned implementation of SafeCoin, coloured SafeCoins should be very easy to create.
Get your hands on a number of SafeCoins.
Make a list of the unique ID’s of those SafeCoins.
Sign the list, upload it to SAFE as a public file without an owner. The list is now immutable and accessible for anyone at any time.
Create a wallet (or wallet plugin) that reads the mentioned list from SAFE and cross-references the ID’s in it with the SafeCoin ID’s in the user’s wallet, and then visually marks those SafeCoins as being the special coin type of your service.
Distribute the coins to your public.
Note that subdivisions could automatically inherit the “coloured” status of it’s parent coin if desired. Also note that the SafeCoin can still be used as a regular SafeCoin. People without a supporting wallet won’t see it as any different.
However, if it is decided to go for a decimal SafeCoin system a la Bitcoin then this method won’t work anymore, since SafeCoins won’t have unique ID’s anymore.
Just like any SafeCoin, after it’s destroyed at some point it will be farmed again. It will keep it’s coloured status, since nothing in the reference file has changed.
I tend to view this as more “tainted” safecoin than coloured. This could affect fungiblity. Not that the practice could be stopped, but I’m not sure how it would be desirable. It’s sort of like superimposing a stock certificate stamp on a $100 bill.
I think the network will be quite capable of making other digitally secure and limited property, and so would rather see safecoins kept as undifferentiated as possible.
Hmm… I think colored safecoins could be useful, but maybe you’re right. It will also probably be easy to implement other non-blockchain cryptocurrencies on top of SAFE.
When we get SafeCoin subdivisions this could be applied to the smallest unit possible.