textbox backcolor - choose from a color palatte problem- HELP

I have a textbox component on my form. I place a buttonbesides it and name it "btnColor". Everytime when user click at the btnColor, i want the system to display the color palatte so that user can choose any color they like. If they choose the color "red", the textbox backcolor will changed to "red" then. Can anyone help ?? What code should i put inside btnColor_Click ?? Thanks in advance