New construction with pre-finished Lyptus floors in their "natural" finish. We had the stairs fabricated out of Lyptus also (bare wood) so they would "match". Before the contractor started finishing the stairs, we pointed out that the stairs seemed quite a bit lighter than the floors, and not just lighter, but blonder for lack of a better word - they lack the pinkish-orangish tone of the rest of the floors. Contractor said "no problem, we'll just use an amberizer in the finish". Contractor gets 2 coats of Trek+ on the stairs, they are still way too light, and now he is gone (for reasons I won't go into here). I found a reputable floor finishing shop and owner said amberizer won't do it, that I can tint an oil based poly with oil stain to modify the color, let it dry a week or so, then cover with 3 new coats of LNL 1500 (I was nervous about going back to the Trek having to mix small batches and possibly having inaccuracy in the mixture ratio that way).

So I did it... sanded the stairs, tinted my oil based poly and got the color spot-on gorgeous in one coat. BUT, now I am nervous that when I scuff-sand this last coat in order to apply the water-based poly next week, I will make my color un-even. So my question is, do you think another coat of clear oil-poly will help protect my tinted coat? Would I have to re-sand my tint coat anyway just to put on the second coat of oil-poly?

Any advice would be greatly appreciated.

rule of thumb is to wait 30 days to coat water over oil and 10 days for oil over water. You have to wait to the film is completely cured or it can blush.

Like Kevin said, wait time is a must when mixing oil and water products.When it is time to scuff your coat , use a very fine paper . 220 grit screen or equivalent paper will work. You could also use 320 grit wet/dry paper under a foam block or whatever you happen to have.

Just make sure you scuff with the grain.Home Depot carries Norton sanding sponges.I like to use the thin red ones .They are labeled 150 grit but cut much more like 220 grit or maybe even finer than that .Those are good for working on nosings.

Ideally, you would coat oil over oil .And in your situation, I would normally want to hot coat the second coat which means as soon as the first coat is dry, you lay the second coat right on top without scuffing.The two will stick well to each other .Then when the second coat dries, you can do some scuffing and apply more coats.

Thank you Kevin and Paul. By the time I started to wonder and posted my question, it was already dry past a hot coat stage (although that would have been better I can see). Since I need to scuff sand anyway, I'll just take your sanding reccommendations and go carefully. And, for as much as I don't want to drag this project out that long, I'm going to wait the 30 days.
Thanks again for the advice.