I have a public property on my web part, that shows in the PropertyGridEditor. It's defined as a type of System.Drawing.Color but it shows as a Textbox in the editor.... Is there a way to use the ENUM type (to get a nice dropdownlist) without having to manually create the static ENUM?

You'll have to create the enum yourself.  PropertyGridEditorPart only supports booleans, enums, strings, and types convertable to string.

If you want your WebPart property to be of type System.Drawing.Color, you can still get an enum in the PropertyGridEditorPart by making your WebPart implement ICustomTypeDescriptor.  You would need to override ICustomTypeDescriptor.GetProperties() to return a custom PropertyDescriptor where PropertyType returns your color enum instead of System.Drawing.Color.  This is possible but fairly complicated.

-Mike

Use this dear

[Browsable(true), Category("Mini Calendar Properties"), Description("Select a color"), FriendlyName("Select Highlighted Font Color"),
       WebPartStorage(Storage.Personal), XmlElement(typeof(System.Drawing.KnownColor))]
        public System.Drawing.KnownColor highlightFontColor
        {
            get
            {
                return _highlightFontColor;
            }
            set
            {
                _highlightFontColor = value;
            }
        }

From Maulik Patel