Get Color Name by Color Code(Hex)

I do not this is is always possible. Since all the HexCodes need not have a named color.

However you can get the color object corresponding to the HexCodes.

Color color = (Color)ColorConverter.ConvertFromString("#hexValue");

also you can use color translator
http://msdn.microsoft.com/en-us/library/system.drawing.colortranslator.aspx[^]
or
Color.FromArgb[^]

to get the background color Name of the control we can :

Color color;
 color = controlId.BackColor; 
 string colorName = color.Name;

If a colour is created from a hex code, it will not have a name, even if the hex code exactly matches that of a name. So if you want to find that name, you'd have to go through all the possible colours (probably by reflecting on the Color class) and see if there's a match.

use script ntc.js

<script type="text/javascript">
        function onBGColorPicked(sender) {
            var hiddenField = document.getElementById('<%=bgColor.ClientID %>');
            hiddenField.value = sender.getColor();
            // alert(hiddenField.value);

            var n_match = ntc.name(hiddenField.value);
            //alert(n_match);
            n_rgb = n_match[0]; // This is the RGB value of the closest matching color
            n_name = n_match[1]; // This is the text string for the name of the match
            n_exactmatch = n_match[2]; // True if exact color match, False if close-match
            //alert(n_match);
            document.getElementById('<%= hdncolorname.ClientID%>').value = n_match[1];
            //alert(hdncolorname.value);

        }
    </script>