Hi Dario,
I sorry about inconvenient, because HoChiMinh's Stock Exchange (VietNam) has trading hour (open stock market) from 8:30 AM to 11:00 AM (GMT +7), if u access in this time, u can see my site how is working? after close time, my site just only show trading results.

1. I fixed error the values that come as "NaN" from the Server (i hidden it).
2. I tried to set the "backgroundColor" instead of the "color" attribute, but it doesn't effect.

Here my changed --> http://www.gls.com.vn:8080/priceonline/test.htm
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function formatValues(item, itemUpdate, itemName)
{
...
var backC = null;
var backH ="#636363";
itemUpdate.setRowAttribute(backH,backC,"background ");

if (illuminate)
{
itemUpdate.setRowAttribute(backH,backC,"background Color");
}

//choose the "change" field stylesheet
var newChng = itemUpdate.getFormattedValue("_change");

if (newChng == null) return;
if (newChng != null)
{
var hotTxtCol = (newChng.charAt(0) == '-') ? "#F70033" : "#2EFF00";
if (newChng.indexOf("-") > -1)
{
itemUpdate.setAttribute("_change","black",hotTxtCo l,"color");
itemUpdate.setAttribute("last_price","black",hotTx tCol,"color");
itemUpdate.setAttribute("lastVol","black",hotTxtCo l,"color");
}
else
{
itemUpdate.setAttribute("_change","black",hotTxtCo l,"color");
itemUpdate.setAttribute("last_price","black",hotTx tCol,"color");
itemUpdate.setAttribute("lastVol","black",hotTxtCo l,"color");

}
if (newChng == 0)
{
itemUpdate.setAttribute("_change", "black", "#FFFF00", "color");
itemUpdate.setAttribute("last_price", "black", "#FFFF00", "color");
itemUpdate.setAttribute("lastVol", "black", "#FFFF00", "color");

}

itemUpdate.setAttribute("_change","bold","bold","f ontWeight");
itemUpdate.setAttribute("last_price","bold","bold" ,"fontWeight");
itemUpdate.setAttribute("lastVol","bold","bold","f ontWeight");
}//end of if (newChng != null)

if (newChng.indexOf("-") > -1)
{
itemUpdate.setFormattedValue("up_down",imgDown);
}
else
{
itemUpdate.setFormattedValue("up_down",imgUp);
}
if (newChng == 0)
{
itemUpdate.setFormattedValue("up_down",imgNochange );
}

//format _change
var newValue = itemUpdate.getFormattedValue("_change");

if (newValue != null)
{
var formattedVal = parseFloat(newValue);
if (formattedVal > 0)
{
formattedVal = "+" + formattedVal;
}

if ((itemUpdate.getServerValue("last_price")) == itemUpdate.getServerValue("ceiling"))
{
//ceiling price
formattedVal = "CE " + formattedVal;
}
else if ((itemUpdate.getServerValue("last_price")) == itemUpdate.getServerValue("floor"))
{
//floor price
formattedVal = "FL " + formattedVal;
}
itemUpdate.setFormattedValue("_change",formattedVa l);
} // end of if (newValue != null)


////format the "number" fields
for (var i = 1; i <= 35; i++)
{
var newValue = itemUpdate.getFormattedValue(i);
if (newValue == null) continue;

if (isNaN(newValue))
{
// ATO, ATC
continue;
}
// neu field co gia tri = 0 thi ko hien thi zero
if (newValue == 0)
{
itemUpdate.setFormattedValue(i,"");
continue;
}

// var formattedVal = parseFloat(newValue);
// itemUpdate.setFormattedValue(i,formattedVal);

} //end of for (var i = 1; i <= 35; i++)


var PriceRe=parseFloat(itemUpdate.getServerValue("ref_ price"));
//format bid
for (var i=4;i<=9;i+=2)
{
//Lenh ATO, ATC
if (isNaN(itemUpdate.getServerValue(i)))
{
itemUpdate.setAttribute(i,"#FFFFFF","#FFFFFF","bac kgroundColor");

itemUpdate.setAttribute(i+1,"#FFFFFF","#FFFFFF","b ackgroundColor");
}

else if (cf(itemUpdate.getServerValue(i))==PriceRe)
{
itemUpdate.setAttribute(i,"#FFFF00","#FFFF00","bac kgroundColor");
itemUpdate.setAttribute(i+1,"#FFFF00","#FFFF00","b ackgroundColor");
}
else if (cf(itemUpdate.getServerValue(i))<PriceRe)
{
itemUpdate.setAttribute(i,"#F70033","#F70033","bac kgroundColor");
itemUpdate.setAttribute(i+1,"#F70033","#F70033","b ackgroundColor");
}
else if (cf(itemUpdate.getServerValue(i))>PriceRe)
{
itemUpdate.setAttribute(i,"#2EFF00","#2EFF00","bac kgroundColor");
itemUpdate.setAttribute(i+1,"#2EFF00","#2EFF00","b ackgroundColor");
}
}
//end of for (var i=4;i<=9;i+=2)
...
}