I bought a number of boards of Sycamore from a local guy with a mill. Although the block-19"X23"X13'-he cut the boards from had actually been cut some time earlier it had been stored uncovered and when it was cut into boards it was very wet and strikingly beautiful with lots of red swirls.
I moved the boards into my shop and let them begin to dry over several months.
I ran a piece of one of the boards recently thru my drum sander and there was no trace of any red.
So why did the red disappear?