Thande
Donor
If you want the boring but realistic answer, part of the 18th/19th century aesthetic is not having logos in the first place, and barely having colours.Oh, what do you think the party logos would look like ITTL?
Otherwise, they might well be based on the colours and heraldic symbols of whichever set of aristocrats controls the local elections, causing colours be different from place to place - as was the case in the UK in OTL into the 21st century, though only a few traces now remain.