Edit in JSFiddle

$(".change").click(function() {
var dictionary= {
"Schwarz":"#000000",
"Braun":"#6F3E18",
"Beige":"#D4BE8D",
"Grau":"#838383",
"Weiß":"#FFFFFF",
"Dunkelblau":"#0000A0",
"Blau":"#345AFF",
"Hellblau":"#32CAEB",
"Türkis":"#22A2A4",
"Grün":"#25B53A",
"Gelb":"#FFFC00",
"Orange":"#FF6501",
"Rot":"#EA0001",
"Pink":"#ED008C",
"Hell Lila":"#9349AA",
"Dunkel Lila":"#663376",
"Mehrfarbig":"#mcol"   
};

$("body *").each( function(){
    for( var ptrn in dictionary){
        $(this).val( $(this).val().replace(new RegExp(ptrn ,"g"), dictionary[ptrn] ) );
    }
});
      alert( "done" );
    
    
});

<input type="button" class="change" value="change all">

<textarea class="input">Schwarz -- doesn't work for text, that was pasted into textarea, onLoad text only....why???</textarea>