Total Sockets
Desired Colors

Craft Type Average Cost
(in chromatics)
Success Chance Average Attempts
Cost per Try
(in chromatics)
Std. Deviation
(of attempts)

Note: Chromatic orbs cannot reroll the same color permutation twice, so the chromatic success chance is always higher than the drop rate.
For mono-requirement items, on-color: 0.9 * (R + 10) / (R + 20)
For mono-requirement items, off-color: 0.05 + 4.5 / (R + 20)
For dual-requirement items, on-color: 0.9 * R1 / (R1 + R2)
For dual-requirement items, off-color: 10% flat chance, regardless of requirements
The formulas and color chances given are not guaranteed to be right (but I tried!)