Robert Oster Orange Zest is a bright red-orange. I have a hard time keeping all of the Robert Oster inks straight, because there are so many amazing colors. I purchased my sample of Orange Zest from Vanness Pens.
Orange Zest is a bright red-orange with some shading and a little bit of sheen.
The ink drops show off the little bit of reddish sheen the ink has.
Let's look at how the ink behaves on good paper first.
Dry time: 42 seconds
Water resistance: Low
Show through: Medium
On Moleskine paper, which is not fountain pen friendly, the ink feathers just a little bit, but does have some bleeding, especially in the flex nib.
I used a broad Pilot Vanishing Point on Tomoe River paper, and didn't have any flow issues.
Overall, the ink is well behaved and is easily cleaned out. I think I prefer Robert Oster Orange over Orange Zest, since there is so much red in Orange Zest.
Disclaimer: I purchased this ink myself, and all photos and opinions are my own. There are no affiliate links on this page.