ID-62 is the improved PQ version of ID-20 PQ which was once commercially available, Ilford halved the amount of Bromide and added Benzotriazole because of customer complaints of colour shifts (warmth).

Dilution does have an effect on image colour with warm tone papers. !+3 was Ilfords recommendations for a dev like this, 1+2 or even 1+1 will give greater contrast and colder tones.

It's a case of fine tuning the vaiables of choice of developer, dilution, exposure and development time that affects image colour with warm tone papers and they are very flexible.

Ian