Are they being driven in series or parallel? If they are in series, then its all fine, since the current though each one has to be the same. If they are in parallel, definitely not. If you parallel leds, the Vf needs to be *closely* matched, even different voltage bins of the same LED wouldnt be compatible in parallel.
Actually, current is important, and yeah they should be in series.
XR-E royals and XP-G whites, which I assume you are using, are similiar enough in regards to current that you can mix them in series and it doesn't matter. Although the XP-G will handle > 1amp current levels better than the XR-E. At 350mA-1000mA in series just treat them as the same LED.
As a side note, mixing blues and reds in this fashion can cause problems if you're driving them hard because they are so different. Blues and white's however are close enough that it doesn't matter.
Oh yeah, if this is a salt tank, do yourself a favor and try a few neutral whites with royal blue along with cools.