The Harveys 777 article and recipe over at unblinking eye may interest you as well.
I know there is controversy if this is the same as the old commercially marketted 777, but I use it, and it works for my purposes with b&w films.
It uses ppd as one of the three developing agents, and that I beloeve may be worth investigating for creating colours. Salts fo paraphenoldiamine (not sure if I have spelled this one right; I think of it just as ppd) are usually what are the key developing agent to the different standard colur developmers lal CD2, CD-3, and CD-4.
Wear gloves; ppd is not too nice. Plus I run 777 as a replenished tank, and the buildup of silver etc leads to terrible stains that only show up the next day after your hands get exposed to natural light.
I sourced my ppd from Ciare at jdphotchem; she is winding down her business I understand. I don't know who else sells it. I suspect that the formualry would not be able to mail it to me across the border.
On another tack, for interesting experinentation, I ran films in what Kodak would call an exhuasted unreplenished e-6 process. Kodak rates it per my calculations for 4.5 - 35mm 36exposure films in 500mL of solutions. I ran a third pair of 36 exposure films through the same chems, to see what happens. The density is very high ( as would be expected, since the first developer has pooped out and thus after the reversal there is an excess of material to convert to silver. The colour developer is also mostly exhausted, and this leads to almost a pointilist painted look to the image. It is for a hybrid work flow to be sure. I have not yet scanned to take he density back, but am keen to see what the end result it. I suppoe if I had stretched the time for the first develoiper from the normal 6 to 6:15 to say 7 or 8 minutes I might still get the good denisty, but perhaps still the waek colurs since most of the colour developing agent is exhausted.