Capping color question

[Paynesgrey]

I notice that honey is capped with bright white cappings, but the brood cappings always look tan, even when I can see a that a bee is still working on closing one. What causes the difference in color? Are they re-using wax for the brood cappings? Adding something different to the brood cappings wax? Perhaps unanswerable, is there a reason that they use different color waxes?

[FRAMEshift]

Honey cappings made by Italian bees are white because there is air under the cap.  The honey does not fill the entire cell.  Some other types of bees do not make white honey caps.

[TheMasonicHive]

When bees first draw their wax it will be white.

When brood is capped it will be given a tan, slightly sunken, porous capping so that the pupa may be fed.  During this time the pupa is has constructed a cocoon.  This cocoon will be cleaned up but over time will discolor the wax to make it gradually darker and darker.

In short, tan cappings = brood and white cappings = honey.