Flo's come in several varieties. Depending on the situation, they will use what best serves the occupants sight.
T12, T8 and T5 are among the most common. They vary in intensity from 12 the lowest to 5 the highest in that lineup.
To answer the question, it is more or less intensity (lumens) that the plants react to.
I use t5's for seedlings through 2 weeks, then roll out under a hid. Depending on your purpose, you can use 6500k for veg and 3000-3500k for bloom, or if your fixture has multiple bulbs, use a mixture of the two to cover more of the spectrum.
Peace and Great Grows
Asmallvoice