Confused about color gradient

Hello - Im trying to make what I thought would be the simplest possible color gradient, but for some reason its not working. I have a rectangle, and I want it to go from the red that I select to blank white linearly. So I put two color stops, one with red, and the other with white, and the midpoint right in the middle. However, the gradient doesn't want to go full white. The closest I can get is to put the midpoint as far over as possible to the red, but even then there's always a red hue at the white end.

I wondered if my eyes were doing "eye things" and just blending the red color in, so I put a fully white rectangle next to it, and yes, there is a red hue that persists. I've attached a screenshot of the rectangles with the menu and edit gradient button pressed so its clear what's going on.

How do I get a simple linear gradient from red to white?

Thanks!