An excellent idea. Kind of like “Fark.com” for message boards!
I find that as I scroll down, (and the legend scrolls off the screen) I can’t remember the color code. Perhaps consider having icons that actually say the topic, rather than a plain coloured rectangle.
Better yet, organize your tables by topic, much like how this forum is laid out. Within each topic area, put the newest posts at the top, and drop the bottom one off the list (or to archives if you’re making them).
I don’t know how you’re sourcing these (I assume old-fashioned HTML coding) but also consider putting the name of the originating forum in small print. I know not to click on anything from “nasty sites” when I’m at work, while I can trust posts at SDMB otoh.
Also, on my set up (Firefox browser, 17" monitor) There’s a lot of white space at the top. I pretty much see only the logo and legend and one or two links before I have to scroll down. See if you can’t get that tightened up a bit to bringing things up higher (maybe put the legend off to the side, or make it smaller).
I know the gist of the site cause I read your OP, but somebody stumbling on it may not quite get what it’s about at first glance.
Not sure how the mods would feel about me linking to other boards, but there are some major forum communities missing that you could look at for threads.