|The following is based on pre-release information for the canceled online game codenamed Project V13 and is not considered canon.|
Only mentioned in the the Armageddon Rag, DayGlow is a weapons manufacturer possibly specializing in chemical weapons.
The company was mentioned in reference to the "Chemblaster™ 3000™ CDS," a chemical weapon said to utilize, "DayGlow technology for high-speed/high-accuracy dispensing." As evidenced by the company's name, it is located in Dayglow.
DayGlow is mentioned in The Armageddon Rag, Vol. 4 under Crazy Ivan's New and Used Guns. The DayGlow company was to appear in Fallout Online, Interplay's original Project V13, since abandoned in favor of an unrelated project by the same name.