Reuploaded. It isn't 100% pure, but there is improvement
Is there a program to check if the white surface is pure besides moving the laptop screen up?

Use the dropper tool. Just randomly move over an area and watch for value changes or use an area average if you have that ability.

If your program supports it, use a color replacement tool or the fill bucket, specify a color, and tell it to only replace/fill EXACT color areas (zero upper/lower range or similarity setting.)

This will reveal any uneven area quickly and distinctly. Dropper tool is less destructive, but you have to pay much more attention and be much more resiliant in you efforts to find/spot un-even areas.

Oh, you can also just invert the color of the image. It helps sometimes, depending on the variation range.

There's a bunch of ways you can check for uneven color areas. These are a few of the methods I use. You may want to use an alternate layer for the checks though to be less destructive of the source image you're working on.

Am I the only one that thinks the hair and eyes are horrible?

It is horrible, just like post #82354. Is there a way to fix that?

Edit: Just looked at StahnAileron's image. So it seems like it's still far from perfect.

Here's a sample using my method:

• Sample Coloring

The majority of the image isn't using "pure" white BTW: it's RGB 255,255,253 (0xFFFFFD), but no big deal. I used multiple colors for each area I shaded in to show each area that was exact in coloring.