There would be a difference, but small. The difference in brightness is less than 10% - you probably won't notice unless you could directly compare the two...and even then close to negligible.
You would probably notice any tint change rather than brightness change.
Q4 WH left, P4 WD right.
The warmer tint of the WH over the WD is very noticeable. The extra brightness of the Q4 over the P4 is noticeable but not significant. A Q5 over a Q2 is roughly the same ratio.