Over the last decade, the software product line domain has emerged as one of the most promising software development paradigms. The main benefits of a software product line approach are improvements in productivity, time to market, product quality, and customer satisfaction. Therefore, one topic that needs greater emphasis is testing of software product lines to achieve the required software quality assurance. Our concern is how to test a software product line as early as possible in order to detect errors, because the cost of error detected in early phases is much less compared to the cost of errors when detected later. The method suggested is a model-based, reuse-oriented test technique called Colored Model Based Testing for Software Product Lines (CMBT-SWPL). CMBT-SWPL is a requirements-based approach for efficiently generating tests for products in a software product line. This testing approach is used for validation and verification of product lines. It is a novel approach to test product lines using a Colored State Chart (CSC), which considers variability early in the product line development process.