For use on Miaou (add "color: <#hexcolor || colorname>" somewhere in your profile->about me)

colornames.js

function hashCode(str) {
    var hash = 0;
    str += '!';
    for (var i = 0; i < str.length; i++) {
        hash = str.charCodeAt(i) + ((hash << 5) - hash);
    }
    return -hash;
}
function colorCode(i) {
    return '#' + (Math.min((i >> 24) & 0xFF, 200).toString(16) +
        Math.min((i >> 16) & 0xFF, 200).toString(16) +
        Math.min((i >> 8) & 0xFF, 200).toString(16) +
        Math.min(i & 0xFF, 200).toString(16)).slice(0, 6);
}
function parseNode(node) {
    if (node.classList && node.classList.contains('message')) {
        var user = node.querySelector('.user');
        var username = user.firstChild.textContent;
        user.style.color = userColors[username] || '';
    }
}

var userColors = {}

var chat = document.getElementById('messages');
new MutationObserver(function(records) {
    records.forEach(function(record) {
        [].forEach.call(record.addedNodes, parseNode);
    });
}).observe(chat, {
    childList: true,
    subtree: true
});

miaou.chat.on('incoming_message', function(m){
    if (userColors[m.authorname]) return;
    $.get( "publicProfile", { user: m.author + '', room: m.room + ''} )
     .done(function( data ) {
        var u = m.authorname;
        var c = data.match(/cou?l[oe]u?r: #((?:[0-9a-f]{3}){1,2}|[a-z]{3,21})/i);
        if (c) userColors[u] = '#' + c[1];
        else userColors[u] = colorCode(hashCode(u));
        [].forEach.call(chat.querySelectorAll('.message'), parseNode);
     });
});