It is a strange thought that the colours we see in Autumn, were there all the time. They were just 'overwritten' by the green of the chlorophyll. As the leaves lose this energy-producing, green pigment, the yellows, reds and all those other Autumn colours, begin to make themselves seen.
It's not just the Maples which show some attractive colours. These Silver Birches are also showing the yellows and rusty-red hues among those leaves which are still hanging on to their green.