The answer to 'shut-off valve rusty water' is that a rusty shut-off valve is a common plumbing issue that can lead to discolored, dirty water coming from your faucets. This is usually caused by corrosion and mineral buildup in the valve over time. Symptoms include reddish, brownish, or yellowish water, as well as difficulty turning the valve.
In many cases, you can try to fix a rusty shut-off valve yourself by turning off the main water supply, removing the valve, and replacing it with a new one. However, if the valve is difficult to access, the water supply line is old, or you're uncomfortable working with plumbing, it's best to call a professional plumber to handle the repair.