I just honed a red granite floor and would like to put some darker color back in to it. Is there some sealer or treatment I can apply to darken it?

Yes, there are several color enhancing sealers available that will darken the granite as well as seal it. Check in the resource directory at the back of this book. You may also want to try a mixture of linseed oil and mineral spirits. Start with 50% of each.

CAUTION If you use the linseed oil trick, you will find that this is not a permanent fix. This is especially true for exteriors. Linseed oil will also attract dirt to the surface of the stone and increase maintenance requirements.