I don’t know if it’s a bug or if it’s supposed to behave like that. But even if I collapse the faces into a single point in the UV editor, the color changes depending on where the point is in that single block of color. If it’s closer to another block of color, then I get the mix of two colors. Basically, it behaves like a gradient, even if it doesn’t look like it.
Help us all to help you.
Please give full screenshots with any questions. With the relevant panels open.
Also, include the lecture time and name/number that is relevant to the problem/issue.
This can be done by Blender itself, via the ‘Window’ menu bar top left-hand side.
On that menu dropdown is ‘save screenshot’.