The flickering will be there no matter the color. Red ones will be better than white or blue ones, but that's it. They still have the opposite of a relaxing effect.

Flicker is a side effect of a common method of variable LED dimming. It's not intrinsic to the technology. You can run an LED at a low level with zero flicker.

But I'm thinking of the tea light replacements that are sold for use in jack-o-lanterns. They intentionally "flicker" in a candle-like way, instead of the kind of flicker you describe.

LED devices can also produce a wide range of color temperatures (esp when filtered and diffused), so there's no inherent blue light problem.

Connect an LED directly to a battery (as in many cheap flashlights) and there will be no flicker.

The human retina will perceive flicker above 200 Hz even if you won't consciously be aware of it.

There are a lot of anecdotal stories out there where people get a reduced sleep quality after switching to LED lighting in the bedroom. Is there something deeper to the story? Quite likely. The question now would be whether this affects everyone or if those people are outliers.