I have vegged under nothing but blue LEDs with great results. No reason 'pure' blue fluoros would not outperform white fluoros and probably MH for vegging.

As my blue LEDs power supply fried (DON'T BUY FROM GOTBOOST on E-BAY!), I was looking into a twin PLL biax fluoro setup with dual actinic bulbs that have one bulb centered at 420nm (purple/violet) and one at 460nm (blue).

There are also 'pure' red fluoros (but not in PLL/biax tubes) that I would like to try for flower. Philips Colored Pro T5 bulbs are in 2' and 4' lengths for around $28.