All the alder I have cut in the past few weeks turned very red within a few days of cutting (I air-dried it outside). Even the stuff that I brought right into my shop (which has a controlled temperature) turned very red.
The color results from the oxidation of extractives in the wood. (It is like an apple that turns color after you have taken a bite.)
Kiln drying must start within a few hours to avoid coloring. Steaming can enhance coloring, and will develop uniform color throughout the wood.
Gene Wengert, forum moderator