If you are not using one of the predefined themes you can set the C1ComboBox's VisualStyle property to Custom to create your own style for the C1CombBox control.

C1ComboBox includes the following apppearance properties:

Property	Description
DefaultItemForeColor	Gets or sets the default text color for the items in the C1ComboBox.
DropDownBackColor	Gets or sets the background color for the dropdown form in the C1ComboBox.
DropDownBorderColor	Gets or sets the border color for the dropdown form in the C1ComboBox.
HotItemBackColor	Gets or sets the background color of the combobox items when you mouse over them.
HotItemBorderColor	Gets or sets the border color for the combobox items when mouse over the border.
HotItemForeColor	Gets or sets the forecolor for the combobox items when you mouse over them.
Padding	Gets or sets the padding within the dropdown form.
TextSpacing	Gets or sets the textual parts of the combobox items.