Try it, from +1 to -1 can make a big diff, you can recover a dark clear pic but not a correctly exp but fuzzy pic (from too high ISO). I found that my 40D (and most likely a 50D) gets color perfect providing you can get the white balance right, either in cam or editing where the lighting ALWAYS can be improved in editing, until I can figure out how to tune the magic wand. Here's a couple of your pics with just lighting tweaks with your exposure, focus, ISO, white balance set absolutely text book perfect. I think the best description of what's done is just increasing the dynamic range is all. Try editing a pic into 3 diff pics; light, normal, and dark then clone diff parts together and you can get a pic that's eye popping. There, FM defined, lol! The best part is at this point (you correctly having all the settings right, assuming acceptible ISO noise) is there's no right or wrong, just better and for your personal preference. Again, good pics