You can do some research on it, such as https://www.viget.com/articles/color-contrast
Lighter sights are always easier for reading than dark sites. BUt do a bit of learning or some trial and error and you will fin something that fits. White or dull white with some not pure black text works well as a general thing.
RE: 'steemadvice.online' is now up and running! Celebrating the launch and introducing the community to the project.