How to change auto fill text in submit form?

Can anyone tell me how you can change the auto fill colour of text in a form please. I wanted a black background and white text when people submit information, but my text is not seen in auto fill as it seems to be always black, yet can be seen as a white text when manually typed in. It’s driving me mad…

My reason for wanting to change the submit form colours were mainly because I did not want the “yellow” looking colour as a background in the type box areas and wanted black instead with a white text to work with the theme of the website.

Hope someone can help.