Light Spectrum and Temperature
You’ve probably noticed that house lights usually give off a yellow light. This is called “soft or warm white” and has a light temperature around 2700K (Degrees Kelvin). Plants do better in flowering when their lights give off this yellow or reddish hue. But in veg, cannabis plants do better with a blue or white light or known better as “daylight or cool white”, which is around 6500K (Degrees Kelvin).
If you can only have one light temperature for the entire grow it’s better to go for a soft white. But many growers use a mix of the two for the entire grow because it better simulates the sunlight. They just change the ratio for different grows periods.