Composite structures that have an appearance of an anodized bulk metal but that is non-capacitive and/or radio frequency (RF) transparent are disclosed. The composite structure can be part of an enclosure of an electronic device. The composite structure can give the enclosure a metallic look without interfering with the functioning of some electronic components of the electronic device, such as RF antennas, touch pads and touch screens. Some embodiments involve forming a metal oxide layer and depositing a non-capacitive layer on the metal oxide layer. Some embodiments involve forming an imitation metal oxide layer and depositing a non-capacitive layer on the imitation metal oxide layer.