Do you run carbon at all on the tank? Maybe you can clean up the yellow look by aggressively running carbon... or ozone would be sweet too! After all you don't see corals in the yellow water in the wild, regardless of how shallow (at least I hope you're not swimming in yellow water!
)
Of course it might also be a design flaw of the solar tubes, where it removes UV and maybe a little too much purple/blue so you're left with the yellow spectrum.