I'm color-blind (red-green) as are a small percentage of your other players. Here are the things I have trouble with:
1) I can't tell the difference between common and uncommon (green and yellow) techs. I can see the red ones.
2) I have heard that there are several shades of green techs, but I can't see the difference between these AT ALL (if they exist)
Here are some recommendations:
1) Add symbols of some sort to display common, uncommon, rare.
2) Use shapes to differentiate techs, not just color.
3) Add the percentage chance of a tech being researched to the text (I think this may be nice for non-colorblind players as well)