Solder mask over un-tented vias is displayed in the same color as the via itself. Sometimes this is confusing, because it is hard to distinguish between tented and un-tented vias visually, for example.
Is there a way to display solder mask on vias with the same color as everywhere else?
Not that I know of, but there is a way to display untented vias so they look different to tented vias.
Tented vias and untented vias use the same colour however untented vias appear larger when the solder mask layer is turned on as the solder mask clearance is included.
First turn on both your top solder mask layer and your top copper layer.
Second open the Colours dialogue window and make the following change: Under "Layers" find the top solder mask layer and turn off the check box for "True Width".
You will find now that your tented vias appear as they did before, but untented vias now show the solder mask clearance as a thin circle around the via.
However, in some cases the solder mask is not bigger than the via. In fact the solder mask is bigger than the drill but smaller than the via, e.g. 0.2 via drill, 0.6 via width and 0.3 solder mask.