Hi there,
I have to do a few explanation.

The aquila set with one red in the C note is a special set.
In practice it is similar to the set that has a wound alluminium strings as C note 3rd.
This red string, in practice, replace this wound string: the sound is better and grant a transiction anf your fingers do not became black coloured as always happen with these alluminium wires.
Please, note that the technology of a red C 3rd has nothing to do with the low G 4th reds.
In this case these low G reds has a lot of copper powder inside and so it can be a problem when there are sharp edges around on nuts and pegs
take care
Mimmo