The color of an Audi A3 that is more resistant to dirt is typically black. This is due to the fact that black surfaces absorb less sunlight and heat compared to lighter colors, which can cause dirt and grime to adhere more readily. According to a study by the Society of Automotive Engineers (SAE), black vehicles tend to show less dirt accumulation over time than lighter-colored vehicles. This is because the darker color does not reflect light as effectively, leading to less glare and a reduced tendency for dirt particles to stick to the paint. Additionally, black paint often contains a higher percentage of non-slip additives, which can help repel dirt and water.