..look at the kelvins (K) produced by the bulb..
color temperature n. unit of measure to express the color (spectrum) of light emitted by a lamp; the absolute temperature of a blackbody radiator having a chromaticity equal to that of the light source (see correlated color temperature).
Lamps rated at 6500 degrees K radiate primarily in the blue/green portion of the color spectrum, which mimics the spring and early summer sun and is most commonly used for vegetative growth; those rated at 2500 K radiate primarily in the red/orange portion of the spectrum, which mimics the late summer and early fall sun and is commonly used to induce flowering.
correlated color temperature (CCT) n. specification of the color appearance of a light source, relating its color to that of a blackbody radiator, as measured in kelvins (K). CCT is a general measure of a lamp's "coolness" or "warmness."