How do you sand Red Eastern Cedar/Virginia Juniper?

The city cut down a very large Red Eastern cedar tree at the park and I managed to score some large sections of trunks. Yes, it is very aromatic.

When first cut, the wood is a shocking, brilliant red. There are also gorgeous white swirls that ripple through the wood. Perfect for turning, right?

Well, the problem is when the sand paper comes out. It really surprised me when this dazzling red goes drab and blah so fast.

I mostly turn pecan, hackberry and walnut with a little maple thrown, and usually the more I sand the hardwoods, the better and shinier the piece gets. I supposed it is the saw dust, but even when I try to go over it with a damp cloth it stays so much darker than when I originally shaped it.

I tried to watch some videos, but I don't know what I'm missing. Any pointers?