Lumen output is measured using a green bias, so measuring red light in lumens requires a conversion.. That I don't have here, try look in the conversion threads/search if that interests you
Aka the same light that is 3500k will output more "lumens" than 3000k but that doesn't mean there's less usable light, just that the unit lumens favors the 3500k because its more green/less red than 3000k..
Edit; check out the 80 vs 90 cri threads/posts. Basically we want our lights with lots of red, and the higher cri and lower kelvins seem to be giving us that.