Something I've been asking myself as well. Everything I've put under my predominant red led, has thrived, even in veg (it's a cheap durolux). I've excluded it this time to see if there is much difference, using a johnston cob, an HLG led, and a Durolux led (blue,white) right now (under 150 watts total), it looks a bit better with exclusion of the reddish led. Combining the 2 Durolux led types at first did increase production and potency, no foxtailing at all. However, my veg just using the durolux white led and the HLG produced massive growth that I want to approximate during flower with the introduction of the johnston cob and the excluded reddish led. A series of incremental changes seems to consistently increase quality and yield of produce.