Yes it could turn blue because when DD it will draw around 14A of current!
Thanks to L4P I was probably first person in a world to test this White Flat 2 emitter with my redneck test(battery, lux meter, clamp meter tail readings) which is not so accurate as pro equipment but it is telling certain values:
Samsung INR 30Q FET Driver:
4.2V, 13.4A, 930 FC
4.0V, 12.5A, 950 FC
3.9V, 11.4A,1050 FC
3.8V, 10A, 1250 FC
3.7V, 9.20A, 1200 FC
3.6V, 8.20A, 1150 FC
3.4V, 7A , 1100 FC
It really is beautiful emitter but it will never go to mine single 18650 configurations because for best performance it should be hard driven.
And when driven on 4.5A old dedomed XPG2 will be better performer.
WF1 is different story… Only flaw is that it is very small emitter for larger aspherics but it should work more than fine in this OTR.
And man you gotta get yourself lux meter and clamp meter (30$ of investment).
Oh forget about that now I see that you have lux meter 
BTW I have same light meter as you. Try to switch to FC mode. That way it reads much more accurate and it is very easy to convert FC to lux online.
5m measurements and convert…