swa66 - 10:06 pm on Oct 28, 2006 (gmt 0)

Remember that the colors a monitor can produce is limited. E.g. try a light yellow on a CRT and on a LCD (no matter how they are calibrated). Same for orange. Typically they show something very different. Same for a true 100% cyan, a monitor just doesn't produce that color, while in general any printer is really good at it.

For a monitor: use RGB colors and try it on as many monitor as you can see to make sure it doesn't go off too far. Especially with the colors a display has trouble with testing is the solution.

Calibration will yield you the assurance you are right, unfortunately most monitors are not calibrated at all. So yes a calibrated monitor should be used in the test, but you should also view it on a CRT, on a laptop, ... and be sure
it always looks acceptable to your customer.

E.g. a customer having a logo with a yellow in it, make sure it doesn't turn into what some would call orange on some CRTs.

Pantone is for printing. Unless you typically would print your web creations, don't worry about them.

Pantone reference cards are a good way of communicating colors, of having predictability, but it's for printing, not for displaying. So yes you can use them to communicate but they define a full spectrum, and reproducing that spectrum with just rgb values isn't possible, let alone dealing with mixing them.