Can you provide me with a formula for RGB values given Munsell coordinates?
Actually, I can’t. First of all, RGB is not defined and depends on the monitor, operating system, etc. Even if you had calibrated RGB, there are still no formulas to convert to/from Munsell. A lookup table is required. GretagMacbeth provides some conversion freeware and you might also look at the tools at easyrgb.com to get some approximations.