The colors that are seen when sunlight is split by a prism are sometimes called the spectral colors. These are red, orange, yellow, green, blue, indigo, and violet. These ROYGBIV colors are often reduced to three red, green, and blue-violet which are the primary colors for the additive color system (light).
Growing coleus from seed. Coleus seedlings are abundant with varying shades of color from the moment they pop through the earth. Their vibrant colors are intensified when grown under fluorescent lights. An abundance of light is a must if you propagate coleus indoors in January.
Some varieties of coleus may produce their best colour in light shade, while others look best in bright lighting. Sowing: Sow all year round or in Late Spring for outdoor plants Sow all year round for pot plant . For the garden, sow 10 to 12 weeks before the last expected frost , they will then be well developed when it is time to plant them outdoors. Sow seeds onto a layer of moistened, sterile potting soil in a shallow tray, do not cover as they need light to germinate.