Is it possible to connvert Pantone colors to RGB? From what I can tell you would need a lookup table of some sort. With thousands and thousands of colors I would never want to maintain this myself so does anybody know of an api?
We use Java so a Java api would work best.
This is generally not possible, as a Pantone color is defined colorimetrically under specific lighting conditions, while RBG colors are at the mercy of the display gamut and calibration.
In other words, a specific RGB color will display differently depending on the color space (sRGB, AdobeRGB, etc) and also on the calibration and color gamut of the monitor on which it's displayed. There's a whole industry around monitor calibration tools and software, but only graphics and photography professionals generally use calibration.
In short, if you (or anybody) were to come up with a mapping table, it would be valid only for a specific computer and monitor combination, and would be visibly incorrect on many, if not most, other monitors.