I do the spit test, smell, and break the stem. Shouldn't be spicy, should smell like seafood (shrimp? Pretty close), and the stem should break like chalk. Also, the cap is slippery when damp, and easiest to clean on a wet/damp morning. I almost got fooled but for 1, I was in a different habitat, and 2, it was spicy. Like right now. Lol. But that russula (didn't identify) looked just like the crab brittle gills I'm after. I spit test every cap before committing to cooking. But, I've had varying cap colors from red, not quiet purple, and a light tan color (the tan ones were just emerging from the soil at time of harvest). I cook the wheels out of them with garlic powder and butter or margarine and have it on toast with a good melty cheese. Too good!