QGIS » QGIS Application

Good idea!

Which dialogs do you think need this? And what would you want to see in the tooltip.

Yes, very good idea. This can easily be added to the QgsColorButton class. I'd suggest a tool tip like:

Hex: #value
R,G,B,A: value
H,S,V (H,S,B): value

Could also have H,S,L. It kind of varies between platform color pickers whether H,S,L is used. Qt's QColor has both H,S,V and H,S,L functions. On Mac, it is usually H,S,B.

It could have a title like '<b>Color</b>' or none.

There seems to be a common 'color select' dialog that is used for fill color, font color, border color, custom color ramps etc. So I guess all of them ideally. In terms of what to see, I had originally thought a color name for the 'basic colors' that are displayed in the grid. Such as 'Dark Green', 'Red', 'Light Blue'. But the idea of having more detailed information on the color in the tooltip could be really useful. It would mean that it could also be used for custom colors, which wouldn't have pre-defined names.

There is QStringList QColor::colorNames() which returns a list of known color names. I have 148 entries here. I suspect it would not affect performance too much to create a Color => String QMap / QHash and look a pretty name up if available. This one could be shown along with the detailed RGB / HSV et al value.