Walls and Ceilings - Dull Cedar Ceiling Needs Updated Look

I have a vaulted cedar ceiling in the living room that I would like to give an updated look or shine too. It is composed of cedar tongue and groove siding, is rough in texture, and is light brown in color. It is in great condition, but looks like it has darkened over the years or maybe had a light stain years ago (house was built in the 70s). I really don't want to paint it, and would like some sort of acrylic or polyurethane to shine it up. I took a spare cedar board from another part of the house that was similar in color/texture and brushed Minnwax High Gloss polyurethane on it to see what kind of outcome I would get. After 3 coats, the Minnwax gave the cedar a shine, yet darkened it greatly (dark brown,almost black in spots). It looks as if the rough cedar was really soaking up the polyurethane. Should I use a sealer before applying the polyurethane? What type of sealer, since waterproofing isn't really an issue? Maybe a cedar stain with a shiny finish or some sort of clear acrylic? Any help is appreciated, thanks a lot.

I had a house once that had a wood ceiling that I wanted to brighten up. I used a semi-transparent white stain. Did wonders for the room and I thought it looked really good.

Cedar can be difficult to stain a light color - tannins are apt to bleed thru discoloring light colors. Oil base varnish/poly tends to darken wood when applied - cedar even more. You might try using a water based poly/varnish. The waterbase finishes aren't quite as shiny as oil base but it won't darken the wood

btw - welcome to the forums!