Beautiful discoloration in redwood. Please help! Need info

Why are you washing the wood with water after sanding the surface? The pictures are hard to figure out what is going on.

-- earthartandfoods.com

First, the wood appears to be a redwood burl. The red color may be natural dyes in the wood or could have been applied for its previous use. It would be very risky to try to duplicate the color on the top without knowing the cause of the color on the bottom.

-- Phil Allin - There are mountain climbers and people who talk about climbing mountains. The climbers have "selfies" at the summit! Likewise with woodworkers.

Im washing the top off because since it is a river table, when i sand the whole surface epoxy powder flies everywhere and washing it is easier for me to get an idea of how level it is (eg laying a level on the surface and seeing how flat it lays on it) and also how the grain is turning out(if any burly curlys are being exposed). Mind you i am only working with a hand saw and an orbital sander because i am a poor college student.

The pictures are just the bottom surface of the table that the epoxy seeped under and covered. If you look closely you can see the red discoloration juxtaposed to the wood. Here are some pictures of the top of the project.

@phil32 thanks for the reply! It could very well be natural colors coming out. It might be previously dyed wood, but i think the chance of it being natural is a bit higher because i sanded both sides down quite a bit before filling with epoxy