The most primitive stand alone Apple LCD was the blue & white 15" Studio Display at 1024x768. It is a multi-sync display so it will display 640x480. The earliest LCDs from other manufacturers were similar, and some like the NEC 14" MultiSync LCD were putty color, so they sort of match a yellowed IIci.
Before that, there were LCDs in portables, but those can't be driven from a standard video signal - they require direct digital row and column addressing from special video chips on the laptop's motherboard. Your IIci is 10 years older than the first LCD monitors. The early 640x400 and 640x480 laptop LCDs looked like garbage compared to the 13" RGB Trinitron.
Before that, there were LCDs in portables, but those can't be driven from a standard video signal - they require direct digital row and column addressing from special video chips on the laptop's motherboard. Your IIci is 10 years older than the first LCD monitors. The early 640x400 and 640x480 laptop LCDs looked like garbage compared to the 13" RGB Trinitron.