You can use Pinterest, graphicriver, Behance, dribble, and google image search for color inspiration. Search the type of logo you want to create and see what color other designers use. You can use the Colorzilla Chrome extension as a color picker tool. This way you will find the trend and also the right color for design. Sometimes clients don't have any clear idea what they really want so if you can explain why you used a specific color they will understand.