Save some headaches and a LOT of time - order the pre-dyed leather if its' available in the shades you want.
Dyeing it yourself "works", but you're likely going to end up with inconsistent shades (important for those who order 10 or 20 of something and want them to match). PLUS - you'll be out the time
to order the dyes,
to mix the shades,
dip the parts,
wait for drying
and have the ROOM to dry that many parts, while still having space to work on something else while those are drying.
Seriously, if you were making "one of" products, then dye it yourself and store less inventory. But if you're doing "50-100" pieces, buying the leather already dyed is a no-brainer. We've ordered drum dyed black for a long time... since it's SO popular in formed holsters. Yes, I order natural leather- mostly for projects getting tooled - and a few other colors I keep a bit of. But around here, an order of 6 or 8 would be about as big as it normally gets (infrequently goes outside of that).
Wickett-Craig sells drum dyed skirting without a 20-side minimum, if that's your only concern. But if you're making HUNDREDS of pieces and like H.O. leather, I'd suggest just bite the bullet and get the 20. The TIME and LABOR you save will astonish you.