In general, the RGB color model is the most commonly used. Input devices such as digital cameras, mobile phones and video projectors use this model. Electronic devices that use the RGB model for output are televisions and computers. The HSL color model is used mainly for webpages.
You can use precise colors, such as a specific blue in a company logo, by copying the RGB or HSL codes from a sample.
More on Color in Presentations
Background Colors in PowerPoint 2010
Print PowerPoint Slides in Color, Black and White or Grayscale
Change the Color Scheme of a Design Theme