Why when I copy an image in Photoshop 2021 and paste it's not the same color.

[imtswhite@att.net]

Why when I copy an image in Photoshop 2021 and paste it in the same picture it has a different  color and tint.

[Mylenium]

Without any info about your color management settings, your system and so on nobody can tell you much. That would typically only happen if a wrong profile is set for proof preview vs. the actual document color space.

Mylenium