last night right before I fell asleep, I was gonna ask for that, some form of box to show the current color.
But I was thinking placing the "swatch" on the php page.
I think I've decided what my first project's gonna be,I'm gonna combine my nightrider bar, an RGB LED and a diffuser vase to make some sort of "choose your color" thing on my site. Then have a 1 second update webcam
Sounds very, very cool! Looking forward to bugging you with changing the color of your RGB-thing. 
Hehe. What are you planning to do with the Knightrider bar, exactely? To add more than RGB-control you'd need to implement commands of some sort, so instead of just sending 3 bytes that are interpreted as RGB-values, you'd use something like 2 bytes pr color, with R/G/B followed by a byte to specify the value of the color.
That way, you could add a command like K and have the following byte speficy one of 256 pre-programmed patterns for the Knightrider bar, or even use the pin-numbers as the command byte and the second byte as the value to write to the pin.
Looking forward to seeing your results!
By the way, where have you gotten RGB leds with matched light intensities? Tried some colormixing once myself, with trash leds I had lying around but of course the intensities of the 3 colors were nowhere near the same so it didn't work at all. x)
Btw2, by '"swatch" on the php page.'", do you mean you want to see the current color of the leds represented on the webpage? A simple thing to do, if one knows how. I'll see if I can't hack something up for ya. ^^