Unfortunately as soon as it's gone pink there's no changed it back, having said that you could try bleaching it but I don't know how much that would improve the colour.
Sycamore is one of those timbers that quickly degraded, even if you manage to kiln it in time it's shelf life won't be great and therefore it needs selling and converting to a finished product pretty quickly. We try to buy our sycamore around this time of year as the cold morning are getting more common, any stocks that's left by summer will go on special as miss matched boards or degrade to make space for the following winters cutting.
We don't keep spalted boards and until a few years back a lot of sawmills would simply destroy the spalted boards as they were seen as poor quality stock. The big head turner is always the rippled sycamore, we always aim to get our hands on some good quality rippled logs, these often sell before cutting as some people like to buy in advanced knowing that the cutting season is nearly upon us.