On sloping top tubes, Rocky Mountains had flat top tubes until they met Paul Brodie. And the Cascade range that Joe Murray designed for The Bicycle Group also had flat top tubes. Then TBG changed the name from Cascade to Kona and Joe Murray worked with Paul Brodie on them. Hey presto, Konas had sloping top tubes.
I believe TBG was the US distributor for Marin and ran their race team. Joe Murray was a Marin team rider, hence the association with him.
Brodie was an artist before going to RM to work as a painter. There he learned to weld and then set up on his own. The 1988/9 and 1990 ranges of Kona were welded in Taiwan and shipped to the USA for Brodie to finish them (braze-ons etc) and paint them. I assume that he must have been responsible for the design of the paint work as well.
From 1991, the association with Brodie ended and the bikes were finished, painted and assembled in Taiwan. Spatter disappeared and the paintwork became plain. I expect getting spatter right isn't as easy as it looks - if you're going to have it, best to have it done by an artist.
Some credit for the plentiful supply of early Konas here must go to JP Saville, the proprietor of the importers Second-Level Sport. He imported Kona right from the beginning and told me that he was initially taking over half of their total production. He now runs Quest Adventure Sports in Worthing.