LTownsend, Welcome to the Do-It forums. Lots of help here.
As Fisherman suggests, the smoke is easily gotten with small additions of black.
The chartreuse does have just a smidge of green in it and your standard chartreuse colorant should get you real close. I'd skip the white myself and use the toothpick in green chartreuse or you could use the toothpick in some blue, very little of the blue. If you really want to play games with the chartreuse you can add some blue hi lite and it'll do things colorant won't make it do.
gain, welcome aboard!