The color you see from sepia toning comes from a different mechanism compared to tanning of the gelatin layer, and it will look as shadow to paper, making no or little difference. In addition, sepia toner doesn't make most films (bromide and iodide rich emulsion) look warm brown as it would many papers.(posted 8085 days ago)I recommend against blue toners as they are very not archival (unstable metallic compounds are used, such as iron).