I use Tropical Toasties, with the deerskin kneepatch. All winter long, both as riding breeches for schooling and foxhunting and as long underwear under my wranglers when working cows. also will add a thin layer of Irideon Supplex long underwear for colder times (I live in Montana).
I see that Tropical rider now has 3 versions of the Toasties..I use the plain original version.
I use the original clarino full seat version of the Tropical Toasties. They are very nice! Just a hint, plan ahead if you need them. It took a full three weeks for mine to arrive from the day I placed the order.
The Toasties come in "camel" color which is a tan. They are my fox hunting breeches. It's rarely warm enough here to wear anything else. Tropical Rider might be willing to send you a sample fabric patch if you are really concerned.
Equissentials Arctics are winter breeches made with a specialised Polartec fabric. They'll customize size, colour (green tea, tan, and rust, all of which are OK for the hunt field), modifications, style, deerskin seats, etc, for you.
Do you remember Mason's rust full seat breeches? Those are the equiessential customs. He hasn't been able to kill them, even with interesting encounters with fences, gates and ground. They are probably 6-7 years old and still going strong. They have run smallish as they haven't much stretch. You could ask to have a fabric sample. They may have improved them since then.
I have several pair of the Tropical Riders Toasties, one clarino knee patch(tan) and two clarino full seats(one black and one tan) I also got a pair last year of their Elements which keep the wind out a bit better. I found the elements to run a little smaller due to less stretch in the fabric. On really cold days, I may add a thin long underwear, but I find them very warm.