Colour in Table column

Hi,

In my table, i have 4 columns. 1-Device Name, 2-Number of Critical issues, 3-Number of Errors and 4-Number of Warnings. I want to fill red color in 'Critical issues" column, yellow in “Number of Errors” column and purple in “Number of Warning” column.

Let me know how to do this. I am using vaadin-6.5.2.

In
public String getStyle(Object itemId, Object propertyId)
function i am getting
null
for propertyId.

Thanks

Already replied
here
.