Replace the hardcoded colors with bootstrap theme colors

This would require being imported as scss, but it would probably be worth it because it would automatically assume the colors of the bootstrap theme.

Start by locating the stylesheets that define the hardcoded colors and checking how Bootstrap is currently included. Determine whether the styles can be imported as SCSS and use Bootstrap theme colors; done means the application builds and its colors follow the selected Bootstrap theme.

Written by the indexing model from the issue text.