If you turn close to their bow you could snag their anchor line and in the process put yourself and the anchored boat in a dangerous situation. That could equate to 50 to 100 feet of anchor line out at the bow of boat that you may be approaching or attempting to pass on the river. Do not shut off your motor until you are certain that your anchor is secure and will not slip off easily. Learn to look at landmarks on the shore to make sure your boat is not drifting after you have anchored. Some of my Shad darts and homemade Flutter spoons use as lures for Shad.
Color varies with water condition and available light.