getHexString( colorSpace = SRGBColorSpace ) {

		return ( '000000' + this.getHex( colorSpace ).toString( 16 ) ).slice( -6 );

	}
Returns the hexadecimal value of this color as a string (for example, 'FFFFFF').

@param {string} [colorSpace=SRGBColorSpace] - The color space.
@return {string} The hexadecimal value as a string.