when the nuva's symbol were stolen, did they lose their mask powers, as they went protodurmis-coloured

Thye probably will have done, as they don't use the while walking in the newewst update to Bionicle.com, and also didn't use the to see through the hills to find out where the tracks led to.

I'm afraid you are wrong. In comic #10, Tahu uses the Nuva Kanohi Hau to protect them from the Kal. He already lost his powers. And Onua (or maybe Gali) says: "We should keep a lookout for the Kanohi Nuva. We could use their help." or something like that.

Moving to Storyline.

::: NN :::

The Toa have to find their masks again. Tahu, Lewa, and Pohatu didn't have a , because only Kopaka has one. That is why they were keeping an eye out. Pohatu could have shared the power of the , but if the Toa went too fast they would not be able to follow the tracks.

They clearly did not lose their mask powers. They did lose their elemental powers
Off topic: I still didn't get comic 11 and it's a sunday so I won't get it today either

They dont, on Bionicle.com, it states the protodermic color is for lost elemental powers, it dos not state anything about mask powers

No.It clearly states that the Toa Nuva lost their elemental powers.I consider this topic a dupe.