Painter's tape is not just blue. There are a variety of products available to use for different types of paint, painting conditions, surfaces, indoor vs. outdoor, and temperature ranges. You can save money with the standard vanilla masking tapes when you are painting indoors and just need a dependable tape that removes easily, cleanly, and gives you a clean paint line.
Blue painters tape can be used indoors, but is made to be used outdoors for up to 2 weeks and still remove cleanly. It is UV resistant.
The green painters tapes are good for some use both indoors and out, but typically have a lower adhesion level than the blue tapes. This makes them ideal for delicate surfaces.