Mvc - login form text input background color

See more:

CSS

bootstrap

Using Bootstrap 5

I want to change the background color of the login credential text input controls I can change the control's background, but there's a yellow mask being applied that keeps me from realizing my nefarious plan. Does anyone know how/where to eliminate this mask?

What I have tried:

I've looked through all of the css files and can't find anything about a mask, yellow or otherwise (it's obviously got an opacity setting applied, but that doesn't help me at all. I've even searched for placeholders and other obscure crap and can't find it.

Update #1 - I added a Html.PasswordFor on a non-account page, and it didn't get a mask on the field. So, now I'm thinking it's a form-specific setting. The search continues...

Update #2 - I created a new MVC5 web app and updated all NuGet packages to the latest versions, and I don't get the yellow input fields. :/