LPD6803 RGB Strip and visualizing colors on the computer

This is long but I tried to provide all the detail I could…

I’ve been working with a LPD6803 RGB LED Strip and I’ve successfully got it working. I eventually (after getting unpredictable results) figured out that it wants values of only 0-31 for each LED (as opposed to 0-255.) Once I figured that out I received predictable results, but here is my dilemma (and an extra question.)

I want to convert these 0-31 RGB values to ones I could transmit to a computer and display the color on the computer screen as well (using processing.) If I use 0-31 where it expects 0-255 I get weird results. If I multiply the 0-31 value by ~8.225 to try to convert it to a 0-255 value I also get weird results.

I found a chart in the datasheet ( http://www.adafruit.com/datasheets/LPD6803.pdf Page 10-11 ) that describes the input data (0-31) vs the duty cycle (0-256) so I figure this may be related. Would I be on the right track if I was trying to use this chart to convert my values to something I could display when the input of 0-255 is expected?

My extra question (which I’m still trying to research on my own) is when I combine two colors, like equal red and green, I’m not getting a yellow that I’d expected. I have to bump up Red quite a bit higher than Green before I get yellow. Could that be a result of how RGB works, or maybe the difference in the eye’s sensitivities to color that I would need to account for?