From a reference photo at the Painting Loft; I zoomed in on the bumpers.
I finally opened up a block of Kilimanjaro paper I've had for awhile and tried it out. It's okay, but, for some reason, I think it responds better is you use a lot of pigment ... I think I could have painted this more lightly, transparently, if I were using my favorite, Fabriano, but I could be wrong--maybe it's just the heat and humidity!
I used a triad of bright violet (Holbein), new gamboge, and ultramarine. Added a bit of azo orange too, which mixed nicely with the bright violet.