The cobalt blue color adds a reflective and protective quality to the lens, allowing it to function both functionally and decoratively. 2 lens covers i got them for the cobalt blue color they display well.
Cobalt Blue Glass Lantern Globe Replacement
Cobalt Blue Glass Natural Rock Basing Material 60g Bag – Scenery Terrain
Vintage "K" Lamp Lantern Railroad Traffic Signal Blue Glass Lens 5 1/2" C04
Signal lamp blue glass lens Lamp / signal Very good condition (EE801)
Vintage Railway Cobalt Blue Ribbed Domed Glass Lens British Railways Board
