Damage can easily occur to your home's siding--whether a ball was kicked at your siding and it cracked a piece of vinyl off or whether during a storm a hail stone broke a hole in the siding. You shouldn't fret about having to replace all the vinyl siding because you don't think you can match the color for a replacement piece. Matching vinyl siding colors is actually very easy.
Call the carpenter that installed the vinyl siding originally. If you weren't living in the house when it was vinyl sided, call the previous owner to find the carpenter's contact info. Carpenters keep detailed records on their projects, so if you can find the carpenter ask him for the brand and manufacturer of vinyl siding he uses and any color names for siding similar to your siding color.
Go to the least visible corner of your home. At the base of the siding on corners is a little bit of overlap at where the siding meets the concrete foundation of your home. Use the sheet metal scissors to trim a thin strip of siding off at this location.
Take the sample piece of siding to your local home or siding store. Show the clerk the piece of siding, and tell her the brand and manufacturer. She can put your sample side by side to stock siding to get you a matching piece.