Thank you for reaching out. Please be informed that you will not be able to change the width or thickness of the frame under design assets. However, you can change the color by following the mentioned steps. Go to Design asset> Choose frame > Toggle on the filter in effects section > Select Duotone > Select any color combination from the presets, or you may customize the preset as per your requirement. It's something we are looking into, though! You can directly let our engineering team know about the other feature by putting up a feature request here.