Electronics360: "U.K. Tomato Growers Use LED Lighting to Improve Yield and Taste"

So that is green LED's for green tomatoes,

yellow LED's for yellow tomatoes,

red LED's, you guess, red tomatoes,

Do not use black light or blue LED's if you wish, the outcome is reasonably undefined...

I never thought the light from LED's has the right color or wave length to support photosynthesis. I might have to think twice and check out the above!