26 is thinner than 24!
I've got a batch of single-strand insulated hookup wire that's 0.6mm, which is between AWG 22 and 23, and that's just thick enough to sit solidly in Arduino female headers (designed of 0.6mm square pins), so I'd go for AWG 24 or 22 rather than 26. For just breadboard use somewhat thinner would be fine.