docs: function(color) {
          if (arguments.length === 0) {
              return this._color;
          } else if (arguments.length >= 3) {
              this._red = arguments[0];
              this._green = arguments[1];
              this._blue = arguments[2];
              if (typeof arguments[3] === "number") this._strength = arguments[3];
          } else {
              // First argument is color name
              Crafty.assignColor(color, this);
              // Second argument, if present, is strength of color
              // Note that assignColor will give a default strength of 1.0 if none exists.
              if (typeof arguments[1] === "number") this._strength = arguments[1];
          }
          this._color =
              "rgba(" +
              this._red +
              ", " +
              this._green +
              ", " +
              this._blue +
              ", " +
              this._strength +
              ")";
          this.trigger("Invalidate");
          return this;
      }