A display device includes a display panel and a light source configured to provide a first color light to the display panel. The display panel includes a first display substrate (DS), a second DS facing the first DS, a column spacer disposed between the first and second DSs, and a liquid crystal layer filled between the first and second DSs. The first DS includes: a first base substrate (FBS); a thin film transistor (TFT) disposed on the FBS, the TFT including a gate electrode, first and second electrodes, and an activation layer; a first insulation layer (IL) covering the TFT and disposed on the FBS; and a second IL disposed on the first IL and including an opening exposing a first portion of the first IL overlapping the activation layer. The column spacer is disposed on the first portion to cover the activation layer and shield the first color light.