Colouring help for animation

ive made an animation, and wanted to start colouring, but every time i try and make one frame coloured, it makes every frame that colour, and im not sure on what to do.

By default, when you draw on a frame in Pencil2D the software will modify the most recent drawing that is visible on that frame. If you want to create a modified copy of the previous drawing instead, you first need to go to that drawing, then press duplicate frame duplicate frame icon. If you don’t like the default behaviour, you can also go to Edit → Preferences in the top menu and change the “when drawing on an empty frame” setting in the Timeline section.