I'm not a surgeon yet, but I'm applying for gen surgery residencies and I'm RG colorblind. From my limited experience, I can differentiate 99% of things including bile from blood. The hardest thing for me to do is to tell erythema on the skin. If it's obvious, I can tell for sure, but the more subtle and light ones are difficult and I'd only notice it sometimes or if someone mentions it and I take a closer look. Remember that as a RG colorblind, you are obligated to not make decisions that are dependent on subtleties between different colors and that you should ask someone if there is a question about colors (ie urine dipstick, path, etc.). Other than that, I haven't had any issues but that's for me and RG colorblindness is a spectrum so what I see is different from what you see. Hope that helps.