fix: _Color type alias of PIL.Image

[Antyos]

The _Color type for Pillow's Image is defined as an integer, not a float.

from PIL import Image
>>> Image.new("RGB", (100, 100), 0.0)
TypeError: color must be int or tuple
>>> Image.new("RGB", (100, 100), (0.0, 0.0, 0.0))  
TypeError: 'float' object cannot be interpreted as an integer

Colors will also throw an error if they are not 1-, 3-, or 4- tuples, and strings can be interpolated as colors.

from PIL import Image
>>> Image.new("RGB", (100, 100), (0, 0))
TypeError: color must be int, or tuple of one, three or four elements
>>> Image.new("RGB", (100, 100), "black")  # ok
>>> Image.new("RGB", (100, 100), "#000000")  # ok

Also, I think #8090 may have missed references to _Box on lines 155 and 178, though I could be wrong. Would that be better as its own PR?

[AlexWaygood]

You've hit a known mypy bug with PEP 604 type aliases: python/mypy#11098

The solution is to use an old-style Union here.

[eggplants]

@Antyos

I think #8090 may have missed references to _Box on lines 155 and 178.

I only noticed the mistake and corrected it while using paste, but did not actually check or verify Pillow's source for the others.

Lines 155 and 178 are suspicious, but you have to make sure their type actually is wrong.

[AlexWaygood]

Also, I think #8090 may have missed references to _Box on lines 155 and 178, though I could be wrong. Would that be better as its own PR?

Yeah, let's fix one problem at a time.

[AlexWaygood]

Thanks, but this isn't quite correct at the moment: see my comment below.

[Antyos]

add tuple[float] to _Color

[AlexWaygood]

Thanks!

[github-actions]

According to mypy_primer, this change has no effect on the checked open source code. 🤖🎉