The nitrifying bacteria that you are breeding during your cycle doesn't require light at all to flourish, and some studies even suggest that UV
light can retard their growth.
So when it comes to that aspect of your cycle it doesn't matter.
As for the algaes, micros and macros, nice ones and naughty ones alike, the light will be a fuel source so take that for what it's worth.
I currently cycle without additional light.
They aren't in total darkness either because no matter where they are in my house or office they still get some daylight coming in the windows.