e, yellow and blue. White is for residents only, yellow ones are reserved, so you can park only on the blue places. The price is €1 per hour and you have to pay from 8AM to 8PM (12 hours). Leave the ticket inside the car in a visible place. Attention: you need coins for the parking - the machine won't accept banknotes or cards.
You can also find 'free' parking at all hours at "Piazzale Michelangelo" on the south side of the town. However, there are time limits for how long you can leave a car, which are rigidly enforced, and if you violate those limits, your car will be towed. It's about a 20 minute walk to the city centre (down the stairs and across the Arno). It has gorgeous views of the city as well.
By bus
Bus stops have clear, schematic labelling of the routes and are all named according to the street name or major landmark nearby. They do not always give an indication of bus times, however, so it is sometimes difficult to figure out how long it may take till the next bus arrives. Tickets must be bought in advance from Tobacconists or newspaper sellers, and are usually valid for one hour over the whole network, so that you can just hop on and off at will. They cost €1.20 for 70 minutes, and multiple day tickets are also available. Tickets are also available on the bus, sold by the driver, at an increased price of €2 (therefore, no more excuses in case of ticket control).
Better value is the €5 day ticket also from Tobacconists or news agents, best to add your name to the ticket and show your pass if needed by ticket control. Same as with cheaper. Tickets on first use need to be inserted into the ticket machine on the bus
