If Dutch was selected, and you just want to make the “D” stand out, you should be able to click the text and set the color property e.g.
Just make sure you click exactly on the letter, so that you can target the innermost container element. If you set the color on an outer container element there is always the possibility that an inner element will override your color setting.
Hey, did you paste that selector somewhere, rather than using MT? If so, try using MT. MT should find a selector that only targets the single element you clicked. The .wpml-ls-display class is used for the other languages too I see now (on closer inspection).
But if you want another copy and paste, try updating the selector to this: