Studies by the USDA's Agricultural Research Service found that strawberries grown on raised beds covered with red plastic mulch were larger and sweeter than those grown on standard black plastic mulch. It seems red plastic reflects higher amounts of growth-enhancing wavelengths of sunlight, which really spurs some plants. Other studies show similar results with basil and early tomatoes, especially in cooler climates.
Two sources of red plastic mulch are:
Harris Seeds, www.harrisseeds.com
Gardener's Supply, www.gardeners.com
Photo from Gardener’s Supply Co.