When you place this control onto a form it changes layout of the form header and borders from standard, platfowm defined, one to custom one. You may change colors of borders and icons as well as icons availability and appearance. To change caption font and color you may change control's font. Do not place more than one control affecting form's appearance onto a form to avoid conflicts. Also please note that this control affects only final form and you will not see any changes while editing control's properties in Form Builder

FormStyleSolid control(widget)