I dont have my notes here with me at work, but the Kodak RA-4 developer sets I have worked with the developer replenisher concentrates comes in A, B and C bottles, with B being the colour developer.
I worked out the ratios when the bottles were full. I am pretty sure the A and C use 50mL/L and the B was something likel 23.5mL/L. This gives you replenisher, which can be used directly, or it can be diluted somewhat and a bit of starter added to '-pre season it'. I go the starter route and add in the replenisher at a rate of 20mL per 8x10.
Blix replensiher is also the working strength.
Both dev and blix can be replenished at a rate of 20mL per litre.
If you are just deevloping in a tray or tube for a small number of prints, not replenishing will not be a big deal, particularly if you are using the dev replenisher undiluted.