HMF Express supplies a grey primer finish on all doors and frames as its standard. The finish has been tested and conforms with testing standards for adhesion (ASTM D4541-02: Standard Test Method for Pull-Off Strength of Coatings Using Portable Adhesion Testers) and salt spray (ASTM B117: Standard Practice for Operating Salt Spray).
If you do not want a primer applied, or you want to request powder-coated finished material for a large project, discuss the options with your sales person before you place your order.