Trend 14: Single color sites - effectively using monochromatic color palettes
Adding white or black to a single color gives you different shades of that color.  To avoid monotony while using a single color, use at least one dark color, one medium/dark color, one medium color and one light color.  This way you will achieve interesting highlights through contrast. Using as single color as a base, use shades, tints and tones to create variations.

These websites were developed in a monochromatic color palette.  Clean, bold, elegant and unified, many of these websites are minimalistic in their presentation.