Monochromatic is a term often used to describe something very blended, with not a lot of hue variety. The sensation this leaves one with can be soothing and calming, yet if we use bright hues, the sensation can be intense as well.
Monochromatic colors schemes are used to create a minimal, yet impactful design that will draw attention to key areas. The base color choice will define the sensation we leave the audience with.
Vibrant Monochromatic:2013 Tracy Berry
Dull Monochromatic:2013 Tracy Berry
The guiding principles of monochromatic color use is that they are somewhat "foolproof" as each color you use is guaranteed to match because they are all shades of tints of the same base color. Monochromatic colors are a safe way to apply color, and this can be one way to make sure that the content is the star of the project and that the design doesn't detract from the content. Keep in mind though that monochromatic colors do tend to have a boring connotation and therefore are not always a popular choice.
Keep in mind based on the scope and purpose of the project, a safe approach is not always a bad thing. Keep it all in context and use that as your guiding principle.