Can you provide information on Ultralume U5000? Also, what are ΔE GE, ΔE Audi,and ΔE PQ?
The only reference to Ultralume U5000 I can find on the internet is in brochures about the KonicaMinolta color control software. Perhaps someone there could let you know exactly what the light source was. Ultralume sources are usually narrow-band fluorescent sources and I would guess that U5000 might refer to a 5000K correlated color temperature. Likewise, the color difference metrics you mention appear to be customer specific. Sometimes instrument manufacturers will add specific equations to their software for certain large customers and then just leave it in for everyone in case they want to use them. I would assume that GE refers to some General Electric specific equation, Audi to the automobile manufacturer, and PQ … I have no idea. They are not CIE color difference equations.
