Mouse cursor invisible in edit screen

I am doing a CSS course now (https://www.codecademy.com/courses/web-ext/projects/html-css-prj_bolt-network), but it is almost impossible to see the mouse cursor in the edit screen. It is black on a grey background. The cursor itself is light-grey and visible.
Is there a way to change the background or the color of the mouse cursor? It is getting very annoying.