To modify a visual attribute:
Tip: To modify a visual attribute at runtime, such as color and font, use the SET_ITEM_PROPERTY Built-in:
Set_Item_Property( 'Blockname.Itemname', VISUAL_ATTRIBUTE, 'VisualAttributeName' );
Where VisualAttributeName is either the name of a visual attribute you've set up in the form (which has foreground, background, font, etc.), or is the name of a logical visual attribute from the resource file.