What light cycle for seedling and veg and bloom switch or just veg?

Heya, I would personally use both switches as the plant will be able to benefit from more than just the one colour of light. I would always use my veg and bloom switch on my blurple for the whole cycle. There are videos out there as well comparing growth rates with purely reds, just blues and then both combined and the full spectrum plants grew much better. Cheers and good luck