I disagree with your other complaints though. Buttons are pretty obvious based on context clues and placement, as are highlights. Text fields also rely on context to communicate their function and furthermore more, they are labeled. As is the colour picker…
I’m curious to see examples of an inline color picker you like, as well as how you generally expect forms to be styled. I looked for a few minutes through some UI libraries I like and basically all of them handle the color picker the same way.
The other pickers have icons to indicate what they are (calendar and clock) so why not a color palette to provide a similar hint?
Needing to read the context to figure out if it's a button or a text field does not help when quickly scanning the page. Figuring out the context and reading the labels is totally unnecessary extra work that a better design wouldn't require.