You can now apply CSS to text in a picker.

Open the dialog box by clicking on the CSS icon, on the right. The style is applied as you type.

The illustration shows the font window open at the same time (optional), allowing you to mouse over font names to change the font.

For example: https://r12a.github.io/pickers/khmr/index.html?text=%E1%9E%A2%E1%9E%84%E1%9F%92%E1%9E%82%E1%9F%92%E1%9E%9B%E1%9F%81%E1%9E%9F%E1%9E%9F%E1%9E%84%E1%9E%9F%E1%9F%92%E1%9E%80%E1%9F%92%E1%9E%9A%E1%9E%B7%E1%9E%8F%E1%9E%9F%E1%9E%B6%E1%9E%9F%E1%9F%92%E1%9E%8F%E1%9F%92%E1%9E%9A%E1%9E%B6%E1%9E%85%E1%9E%B6%E1%9E%9A%E1%9F%92%E1%9E%99&showFonts=true&css=text-decoration:underline%20tan;%20text-underline-position:under