How Bright is 2700 Kelvin or 5000 Kelvin?

As we state in our "Watts vs. Lumens vs. Kelvin" article. Kelvin is not a measure of brightness rather it is a measure of color temperature. If you are looking for brightness, the proper measurement to look for is lumens. In general though, 5000K or cool/daylight white will a appear brighter than 2700K all things being equal but this is due to the higher contrast of such light.