With all the fires in the NW, we're seeing some fantastic red sun rises & sets. However, digital cameras normally can't show the red sun because of the light wavelength. It burns through the clouds and smoke so photos always come out with the sun yellow or white.
What kind of filter or setting is needed to keep the red color?

Sounds like you are overexposing the sun. Does you histogram show the clipping? You may have to underexpose to get the sun, and then blend images together.

Doug is correct. The sensors can only capture a range of about 6-10 stops of light, the sun, even filtered through clouds will still be pretty bright. Underexposing will give you a better shot and blending will fix it. As for the issue of the sun being yellow or white, once you underexposure, or just expose for the sun a simple White Balance adjustment should do the trick or at least get it closer to what you are looking for. Be extremely careful though of leaving your camera exposing to the sun for a long period of time, it can easily burn a sensor.

Thanks guys. Now that the fire is under control and the smoke is clearing I'll have to wait until we get another one to try it.

Of course this is while the sun is setting and isn't as bright as it is while high in the sky, but my camera has various settings for different light levels and applications.

A hard GND should work well in this case

dunno what happened but I got the red. there was a mix of clouds and smoke. I would lift the camera so there was just a little of the mountain/sunset in the frame, push the shutter button to lock the settings,bring the camera down to get the picture I wanted and shoot. the pictures still do not do the sunset justice. it was unreal. the wife and I had to stop the truck, get out and watch the sun set.

I can get the red surrounding the sun. What I can't get is the sun itself when it's a red ball in the sky. The fires in this area area are out now so I can't try again until we get another one (I'll gladly wait, hopefully for a LONG time).