[Small Ticket] Change Color of Labeling in Argilla

[Wessel93]

When clicking the ''Validate'''or discard button, the color change is only minor. Can we make this more explicit:

• Ask David if he knows how to fix this
• If not, figure it out ourselves
• Implement

[jmargutt]

Validate/discard is MUCH clearer in the new FeedbackDataset, I propose to not waste time digging in the backend and just move on to implement it, also needed for #138