Describe the Problem
It is not obvious at all to me that the colour wells at the top of the drawing tool's control panel are clickable and provide access to alternate colours and textures. In fact, after years of using MT, I was completely unaware of this feature until now.
The Solution you'd like
Change the colour wells to look more like those in conventional drawing programs, with the foreground and background indicated clearly by overlapping boxes like this:

At least to me, this would make them more obviously clickable just through familiarity.
Alternatives that you've considered.
In addition to the requested change, I think it could be worth getting rid of the palette in the control panel. For one, I don't find the set of colours particularly inspiring. But more importantly, I've never considered it any hassle in other drawing programs to have to open a colour picker, and it's arguably more important in those than in MT. At the same time, removing the palette would push users more to interact with the the colour wells as there wouldn't be a more straightforward source of colours.
A completely different tack would be adding a little "plus" icon or something to the colour wells to indicate they can be interacted with. But I think this would either be too small to be noitcable or recognizable, or it would be annoyingly large.
Additional Context
This FR is refering to the top two boxes in this control panel:

Here's my attempt at mocking up the feature:

And if the palette were gone as well:

Describe the Problem
It is not obvious at all to me that the colour wells at the top of the drawing tool's control panel are clickable and provide access to alternate colours and textures. In fact, after years of using MT, I was completely unaware of this feature until now.
The Solution you'd like
Change the colour wells to look more like those in conventional drawing programs, with the foreground and background indicated clearly by overlapping boxes like this:

At least to me, this would make them more obviously clickable just through familiarity.
Alternatives that you've considered.
In addition to the requested change, I think it could be worth getting rid of the palette in the control panel. For one, I don't find the set of colours particularly inspiring. But more importantly, I've never considered it any hassle in other drawing programs to have to open a colour picker, and it's arguably more important in those than in MT. At the same time, removing the palette would push users more to interact with the the colour wells as there wouldn't be a more straightforward source of colours.
A completely different tack would be adding a little "plus" icon or something to the colour wells to indicate they can be interacted with. But I think this would either be too small to be noitcable or recognizable, or it would be annoyingly large.
Additional Context
This FR is refering to the top two boxes in this control panel:

Here's my attempt at mocking up the feature:

And if the palette were gone as well:
