XnView Software

This already exists, go to Settings (f12), on the left you should see "File formats", click that and choose the "Clear all" button at the bottom, then select jpeg and png.

Sorry for the late reply, life caught up with me and I've been caught up being a new dad. I love the new dark mode, it's absolutely fantastic. Thank you very much for the work you've put into this incredible software!

There is a new alternative to PNG coming known as QOI (.qoi) (Quite Okay Image format), it is significantly faster than PNG for encoding, slightly faster at decoding, and is still lossless with a similar file-size to PNG. I think it would make a great addition to XnView!

Details:
Reference Encoder ...

i've changed default colors when changing theme, here is a screen...


That is much better on the eyes and is a big improvement! Thank you!
My final request is a second "dark" theme which is darker.

I have edited the previous screenshot quickly it is not perfect but shows an example of a very ...

J'ai constaté que le thème sombre n'est pas assez sombre, qu'il y a trop de blanc dans la fenêtre et que lorsque des éléments sont sélectionnés ou mis en surbrillance, il est encore trop clair pour que je puisse l'utiliser confortablement la nuit. Voir ci-dessous.

I have found that the dark theme ...