Just tried it in a Czech Amber - I used 1.875 pounds in a 10.5 pound total grist for 5.5 gallons. I wanted the color and had it on hand from a club purchase. Base Malt was Weyermann floor malted Bohemian Pilsner and the only other add was a quarter pound of acidulated for pH.
For your Red you might want to push it to a full two pounds or higher...cheers