Hi Leon,
The sites are quite fast and the fonts are served locally so it should not be a problem, but yet it is visible
Locally hosting fonts doesn’t mean the browser doesn’t need to download the fonts, depends on how fast your server and local internet are, I would say it’s quite normal.
If you want to improve this, you can ask the browser to preload the fonts, for more info:
https://web.dev/codelab-preload-web-fonts/
The color issue seems caused by the cache, can you disable the cache plugin you are using to test?