Definition of "redly"

Beams, rods, and lances of energy flamed and flared; planes and pencils cut, slashed, and stabbed; defensive screens glowed redly or flashed suddenly into intensely brilliant, coruscating incandescence.

1948, Edward Elmer Smith, Triplanetary : a Tale of Cosmic Adventure

[…] you can sleep under it beneath the stars which shine so redly on the desert world of Kakrafoon […]

1979 October 12, Douglas Adams, chapter 3, in The Hitchhiker’s Guide to the Galaxy, London: Pan Books

But there are still two alternative interpretations of such expressions as "sensing red" or "sensing redly." (i) We might define "sensing redly" in such a way that our definiens makes explicit reference to things that are red.

1994, John Donnelly, Language, Metaphysics, and Death, Fordham Univ Press, page 208