Keeping Poplar Green?

You might contact Taylor Guitars. A few years back they produced some stunning guitars from just that species of wood. Many of their Liberty Tree Guitars have streaks of green in and among the chocolate and cream colors. Difficult to describe and hard to photograph. The green will not stay vivid. I do know that they use a UV cured Poly. (That stuff cures so fast that another of their guitars that I had a while back had a small bubble burst as the finish was curing, catching the crater as it was collapsing.)

-- "Those are my principals, if you don't like them....I have others." - Groucho Marx