brush color only black

[MaKale Buckman]

ive been using photoshot to edit certain parts of a group of photos that I want to key out later in premiere pro. I lasso the desired section I want to paint over and fill in the section to the color I desire. Ive been using a shade of purple. This has been working very well, but now it only paints in black. even when I change the color I'm using it still only paints in black. this wouldn't be a problem except for the rest of the photos having a large portion of black.

I closed one photo after it being fine, then I open the next photo and that's when the issue started.  

[MaKale Buckman]

so I just tried to erase the black marks I made(because undo wasn't working) and the erase brush marked in the color I wanted instead of erasing.

[Bojan Živković]

When erasing on Background layer it will use Background color to fill erased areas. If you want to fill selection using Background color (purple on your screenshot) please press X to exchange background and foreground colors.

[Bojan Živković]

From what I can see you are in RGB color mode and Foreground color is black. Can you try, aftre creating selection,  using Edit > Fill > Content: Color > color of your choice.

If problem persist try with preference reset, use manual method to drag Settings folder on the Desktop https://helpx.adobe.com/photoshop/using/preferences.html