No idea how well this works but it looked to blend correctly. I am hoping not to get killed for posting this. XD

function blendColors(){
var hexconv = new Array();
hexconv[0] = ["FF","1"];
hexconv[1] = ["CC","2"];
hexconv[2] = ["99","3"];
hexconv[3] = ["66","4"];
hexconv[4] = ["33","5"];
hexconv[5] = ["00","6"];
var hexnums = new Array();
var inchash = false;
if(arguments.length < 2){
var error = new Error();
error.message = "Invalid ammount of parameters.";
throw error;
return false;
}
for(a=0;a<arguments.length;a++){
if(!arguments[a].match(/^(#)?\w{6}$/i)){
var error = new Error();
error.message = "Error in parsing hex value.";
throw error;
return false;
}}
for(a=0;a<arguments.length;a++){
var toaddhex = '';
if(arguments[a].match(/^#/i)){
inchash = true;
var hexcolor = arguments[a].split(/^#/i)[1];
} else {
var hexcolor = arguments[a];
}
for(h=0;h<3;h++){
if(hexcolor.match(/^(\w{2})/i)){
var twohex = RegExp.$1;
hexcolor = hexcolor.replace(/^\w{2}/i,'');
if(twohex.match(/^(FF|CC|99|66|33|00)$/i)){
for(k=0;k<hexconv.length;k++){
if(twohex.match(new RegExp('^'+hexconv[k][0]+'$','i'))){
toaddhex += hexconv[k][1];
break;
}}} else {
var error = new Error();
error.message = "Error in parsing hex value.";
throw error;
return false;
}}}
hexnums.push(toaddhex);
}
var hexpnum = 0;
var fhdigit = 0;
var shdigit = 0;
var thdigit = 0;
for(g=0;g<hexnums.length;g++){
var fsdig = hexnums[g].charAt(0);
fhdigit += parseInt(fsdig);
var ssdig = hexnums[g].charAt(1);
shdigit += parseInt(ssdig);
var tsdig = hexnums[g].charAt(2);
thdigit += parseInt(tsdig);
}
fhdigit = Math.round(fhdigit / hexnums.length);
fhdigit = fhdigit.toString();
shdigit = Math.round(shdigit / hexnums.length);
shdigit = shdigit.toString();
thdigit = Math.round(thdigit / hexnums.length);
hexpnum = fhdigit+shdigit+thdigit;
var finhex = '';
for(j=0;j<3;j++){
if(hexpnum.match(/^(\d{1})/)){
var twohex = RegExp.$1;
hexpnum = hexpnum.replace(/^\d{1}/,'');
for(q=0;q<hexconv.length;q++){
if(twohex.match(new RegExp('^'+hexconv[q][1]+'$','i'))){
finhex += hexconv[q][0];
break;
}}}}
if(inchash){
finhex = '#'+finhex;
}
return finhex;
}

Used like this:

blendColors("hex color1,"hex color2");

You may blend more than two hex colors. Hopefully it works alright.