Not sad or morose, needs to be qualitatively like being under a heating lamp, almost as if one were cocooned or swaddled in warmth.

• Probably "dark" is preferable but not necessarily,
• must be "warm", can be "chill" but not at the expense of warmth,
• probably "soft" or "easy"/mellow, intensity should be fairly homogenous throughout
• "sonorous", "fat", possibly resonant is good
• definitely not cold/cool or desolate
• buzzy/buzzing/buzz/swarming/swarmy, oscillating, vibrato, very mild distortion or driftiness, like bees swarming
• dreamy but still warm (opposite of inception)
• ethereal is ok but not in conflict with warmth
• liminal is ok as long as it doesnt conflict with warmth

Harold Budd - Niki D (album: Luxa)

Sirena Beach from Mario Sunshine (very similar to Niki D)

Brian Eno - Neroli

Burst Error - Warm Reset

Earthbound - Buzz buzz prophecy

This is all very subjective so take all this as more general but try to recognize the spirit of what is being sought. A lot of this sound makes me think of if microwave rays were embodied in sound