The snake is telling you what it needs.. humidity, that is why they soak. They also soak if it is too warm in the cage. Either case, the snake is letting you know. Are you using a thermostat to prevent against overtemperature?
If I remember correctly being in Colorado this time of year, humidity gets low.
A suggestion for you: use moist coir fiber a the substrate and see what happens. You know, Bed a Beast, Eco-Earth and those type of products.
Lamps dry out the air even more. OK if the substrate holds moisture. Make it deep enough for the snake to easily submerse itself in the substrate. I put in about 3-4 times the thickness of the snake. You'll notice a huge difference in skin tone and possible even feeding response.
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Mark