> colors2 = "cyan   forest green  burnt umber".split()
> # oops, not what I wanted, quote each separately

It isn't shared by the proposal.

  colors2 = %w[cyan   forest green  burnt\x20umber]

I don't get it. There is weird escaping of spaces that aren't split? That is confusing and a bug magnet. What are the rules for escaping all whitespace, exactly? All the Unicode space-like code points, or just x20?

Plus your example doesn't capture the color "forest green" correctly in any way I can imagine.  But I suppose more weird escapes in the middle could do that.

Overall... the proposal becomes incredibly ugly, and probably more characters that are harder to type, than existing syntax.
Keeping medicines from the bloodstreams of the sick; food
from the bellies of the hungry; books from the hands of the
uneducated; technology from the underdeveloped; and putting
advocates of freedom in prisons.  Intellectual property is
to the 21st century what the slave trade was to the 16th.