Switching to an alternate style variation, inside the editor, is instant. Click one of the tiles and the visual is shown immediately:

If you then save the changes and preview the site frontend, however, the styles take a while to settle in. The following GIF shows changing a style, opening the frontend in a new tab, and then reloading the page over and over to see what takes:

Note that the typography and a few of the style changes are immediately shown. But things like background colors take a while, up to several minutes. Clearing the cache doesn't make any difference.
Steps to reproduce:
- Use a block theme, such as TT3 or TT2
- Go to the site editor
- Switch to a different style variation (Click global styles > Browse styles > Pick one). Save the changes.
- Click view > View site. Note that the new styles aren't applied immediately. Wait up to several minutes to reload. Eventually the whole style is applied.
Tested in Chrome on Mac.
Switching to an alternate style variation, inside the editor, is instant. Click one of the tiles and the visual is shown immediately:
If you then save the changes and preview the site frontend, however, the styles take a while to settle in. The following GIF shows changing a style, opening the frontend in a new tab, and then reloading the page over and over to see what takes:

Note that the typography and a few of the style changes are immediately shown. But things like background colors take a while, up to several minutes. Clearing the cache doesn't make any difference.
Steps to reproduce:
Tested in Chrome on Mac.