Incorrect GIF palette in frames after the first

[sliva0]

Code and Image

Image (ralsei.gif):

from PIL import Image

image = Image.open("ralsei.gif")
image.seek(4)
image.save("ralsei.png")

What did I expect to happen?

The script saves the fifth frame of the gif into a .png file.

What actually happened?

ralsei.png:
The script saves the fifth frame of the gif into a .png file, but without the yellow stars, in their place are completely transparent pixels. Possibly due to the fact that there is no yellow in the palette of the first frame.

OS, Python and Pillow versions:

• OS: Windows 10 Pro 20H2
• Python: 3.10.0
• Pillow: 8.4.0

Also reproducible on:

• OS: Manjaro Linux (arm)
• Python: 3.9.7
• Pillow: 8.4.0

[SandaruKasa]

Can't reproduce it on Kubuntu 21.04 x86_64 with Python 3.9.5 and Pillow 8.1.2.
ralsei.png:

But with Pillow 8.2.0 (and 8.3.2), the stars disappear and the background turns black.
8.2.0:
8.3.2:

With Pillow 8.4.0, however, the background is back to normal, but the stars are still missing.
8.4.0:

[radarhere]

I've created PR #5857 to resolve this.