HEXコードをRGBに変換する関数

function hexToRgb(hexType){ 
      var hex = hexType.trim().replace( "#", "" ); 
      
      var rgb = ( 3 === hex.length ) ? 
          hex.match( /[a-f\d]/gi ) : hex.match( /[a-f\d]{2}/gi );     
      
      rgb.forEach(function (str, x, arr){     
          if ( str.length == 1 ) str = str + str; 
          
          arr[ x ] = parseInt( str, 16 ); 
      }); 
      
      return "rgb(" + rgb.join(", ") + ")"; 
} 

RGBをHEXコードに変換する関数

function rgbToHex(a){
  a=a.replace(/[^\d,]/g,"").split(","); 
  return"#"+((1<<24)+(+a[0]<<16)+(+a[1]<<8)+ +a[2]).toString(16).slice(1)
}