When using my iPad, I have the screen set for a dark (black) background with white lettering. The chords show as yellow. Very easy to read. When I view the document on my computer with the Bandhelper web page the background is white and the chords in yellow are very hard to see. Is there a way to make the website view documents like my iPad?
No, the website doesn't have a dark mode.
The yellow used on the website is darker than the yellow used in the app in the dark color theme, but if that's still not enough contrast, you could set Settings > Appearance > Chords Color to another color, like orange.