Coated article comprising colloidal silica inclusive anti-reflective coating, and method of making the same

A method of making a coated article, the method comprising:

• providing a glass substrate;
• preparing a sol, the sol comprising colloidal silica having a particle size of 10-110 nm;
• spin coating the sol, directly or indirectly, onto the glass substrate;
• curing the sol to form a silica-inclusive anti-reflective (AR) coating, wherein the curing comprises exposing the substrate together with the sol spin coated thereon to first and second elevated temperatures, the second elevated temperature being higher than the first elevated temperature, wherein the substrate together with the sol spin coated thereon is exposed to a temperature of about 150 degrees C. for 2 minutes, followed by a temperature of about 220 degrees for 2.5 minutes;
• and
• heat treating the glass substrate together with the AR coating at a temperature of at least about 500 degrees C.,
• wherein, post heat treatment, the AR coating has a b* value of 0.8 or greater.