I once bought an ipé decking board that was greenish brown. Especially when it was freshly sanded/scraped, it really had a greenish tint to it, not reddish at all. It also had white resin ducts, as opposed to the yellow resin ducts we find in most ipé. I picked this board mainly because of its exceptional density. I later determined the board to have an SG of 1.18 at EMC. Very dense, even for ipé. This board was not the typical ipé I've seen, but it made good bows. The word "ipé" is a pretty vague name anyway, for a number of botanical tree species in the genus Tabebuia. Perhaps the greenish brown type of ipé just comes from a rarer species of Tabebuia. Just guessing.
I hate the term "ironwood", though. At least fifteen species carry that false name, and nobody will know for sure which species you are talking about here at this internationally oriented forum.
If you don't like the natural wet hairball brown color of your piece of ipé, you can only stain or paint it. There is no way to treat it so its natural color magically changes. Since it is pretty dark by itself, your best bet would be to stain or paint it even darker.