How to use jQuery to change the backgound color of a textbox?
Better practice is to seperate UI from logic, in your case:
$("#textboxid").addClass("aClass");
If you really need it your way, then do the following:
$("#textboxid").css({"background-color": "color"});
Replace #textboxid
with the desired selector, and color with the desired color.
Note the following does the same for one property:
$("#textboxid").css("background-color", "color");