I'm curious why all the tights are the skin-tight versions. Why none of the tights that are looser, with air space between the skin and the legs, like those worn by runners or that were popular during the 70's and 80's? I find that when wearing skin-tight tights they are much more prone to temperature changes and can feel too hot or cold, or vary quickly with winds. When tights are slightly loose the trapped air tends to keep the temperature more even inside and I feel less hot on hot days and less cold on cold days.
The best tights I ever wore were cheap Field-Sensor (polyester fabric) training tights made for high school students here in Japan. The fabric was a tight, mesh-like, 3-D structure polyester (like a thin version of the 3-D mesh used on backpack straps and back panels) that breathed exceptionally well, dried immediately, but also kept my legs warm no matter how cold or wet they tights were. I can still find similar tights around, but for some reason the Field-Sensor fabric seems to have disappeared. The looseness of the cut and the 3-D nature or the fabric are part of what helped the tights keep me warm. Every time I've tried some of the newer, skin-tight tights these days, I always felt the cold or heat much more easily.