Yes, indeed I have done it myself when I started to draw/paint. So in order for you to understand it better I specifically made three examples of one of old paintings I did when started out draw/paint digitally.

Here is an example with black background.

Example of grey background.

And last but not least - white background.

Now after you have observed all examples try to squint your eyes between black, white and grey then watch for highlights on painting. You can clearly see difference when there is contrast.

Hope that helps in your future drawings

Maybe at first you will be okay to use paint bucket tool on your background layer but with time it will become annoying so do this once instead and do not worry about it ever again.

Step 1:



Step 2: