Dear Mr. Buk
Burning in Water color sounds about right, I'd say Dear Mr. Buk is a bit darker. Don't have a copy of BIW here (though I have 3 copies of the original Dear Mr. Bukowski - as I have bought copies whenever possible of this, one of my favorite "collectibles". I really don't collect any books for keeps - read alot of course - but prefer to keep things I can hang on the wall). Thankfully, all but the completists tend to have their idiosyncracies. Can you imagine what prices would be if we all wanted the same thing with the same degree of passion?
As for the ribbon, it is silk (I believe), a deeper color (Krumhansl says brown), textured with short equal lines across its length, and is threaded through the flap of the envelope. The tie wraps vertically around the envelope and is lengthy enough to secure the envelope in a bow, knot, whatever.