The answer to 'gutter grimy' is that gutters can become grimy and clogged due to a buildup of leaves, twigs, dirt, and other debris over time. This can cause water to back up and potentially lead to roof leaks, foundation damage, and other problems. Symptoms include visible grime and debris in the gutters, water overflowing the gutters during rain, and water stains or damage on the home's exterior.
The best solution is to regularly clean and maintain the gutters. This can typically be done as a DIY project, but may require professional help for taller homes or if the gutters are in poor condition. Homeowners should clean their gutters at least once or twice per year, or more frequently in areas with many trees.