Hey everyone, I'm sure this isn't news to some of you but if you watch the tutorial for creating a full site by Sergie, you can see him in the first couple of minutes using a dropdown to pick a css color.
That clever little application is called ColorSnapper. It remembers recent hex and css values and puts them in your menu bar for quick access. You can then select them and it copies it to your clipboard to past anywhere, in this case, webflow.
The other nice little thing about it is you can use a selector to grab color from anywhere on your screen complete with a zoom tool that zooms into individual pixels to select the exact one you want.
Its only 5 bucks on the mac app store. I'm not sure if theres a windows equivalent though.
Hope this helps!