Styling issues with reserved words, require and bytes, in Black theme

[albbeltran]

I noticed styling issues with 'require' and 'bytes' when using the Black (dark) theme.

These reserved words turn to black color when the Black theme is active, making them impossible to see unless you hover over them. Maybe there are more words with this problem.

I also noticed that the words public, view, and returns turn dark green and are hard to see.