Have you contacted Marvin about painting them an other than default interior color.

Marvin will entertain custom interior colors. They will have to be quoted and still be less expensive than done locally. I would choose the shade of white that you want and go from there.

I had not reached out to Marvin directly (but good idea, just sent them an email). We had been dealing directly with our contractor up to this point and he believed that was their only white. I figured it wouldn't hurt to look into it myself.

While it's not ideal having to chase this down ourselves, it's also a good check on his level of hustle before we hire him. Thanks WoW and Eastbay, I'll follow-up with what we hear from Marvin.

Were you looking at it under florescent light?

We looked at it under a variety of lights. We placed it on the existing window casement and it had a distinctive green tint - more like their arctic white (greenish) than stone white.

They replied quickly to my email - Eastbay nailed it when suggesting they'd consider custom colors. We're working with our guy now and hopefully our order is substantial enough (60k+) that they'll do it for us. We're not looking for anything fancy, just a truer white.