Windy state uses the mdi icon with black lines which doesn't match the default color scheme. It also doesn't match the other icons on the weather card.
Also, the new icons are impossible to tell what the state is. Are the forecast states pouring or lightning? I can't tell. Only sunny is easy to distinguish in my view. This partially overlaps with #5676, but I'd like to give a very concrete example of the ambiguity in the new icons.

Use a thematically consistent icon set.
Add a forecast weather card that has an entity with windy condition
Unknown
hmm can you send the State and Attributes for that entity?
I can't reproduce
It is no longer reporting as windy, so I cannot provide, but it looks like it was "windy-variant" by the icon.
The forecast conditions are "lightning-rainy", but it is a bad sign for the legibility of the icons if I have to go to the attributes to know.
https://github.com/home-assistant/frontend/blob/dev/src/data/weather.ts#L3-L22
I see the issue. I changed this to be only images... Not sure how it gotreverted. I will make the change again. Windy-variant should be the same as windy.
Most helpful comment
It is no longer reporting as windy, so I cannot provide, but it looks like it was "windy-variant" by the icon.
The forecast conditions are "lightning-rainy", but it is a bad sign for the legibility of the icons if I have to go to the attributes to know.