With the same transparency (about 60%), it looks quite nice if the background is not too light: https://i.imgur.com/5dDgxIb.png But when the background is too light, it looks very awful: https://i.imgur.com/7BCuWHC.png
Solution: don't use so high a transparency value. 60% is really high. There's not really a good way to simultaneously allow the background to show through, and also keep text readable with all possible backgrounds. This is going to have to be solved with user discretion, I'm afraid.