The answer is quite basic. The different colors on your court cause the asphalt to expand and contract a different rate.
The White color of the lines tends to reflect the suns rays. So the asphalt under the white paint tends to stay much cooler and does not help expand and contract too much during weather temperature changes. The colors next to the white line are usually a darker color. A darker color will draw the heat from the sun. This helps soften and expand the asphalt. The back and forth movement caused by cool and hot temperatures will eventually lead to cracking in the area where the white lines meet the darker court colors.
Once this cracking begins, water will begin to enter the sub-base of the court through those cracks. Water in the sub-base will lead to more major problems and more cracks in the future.
To minimize these cracking problems is to choose tennis court colors that are lighter. Once cracking begins, make sure to seal them closed to prevent water getting into the sub-base by way of the cracks.
