Unlike later home computers that directly output color signals, Woz designed the Apple II to use a side effect of the NTSC color TV standard's backward compatibility for black-and-white televisions. Basically, it cheats. The dependence on NTSC for color is why, as you noted, the separate Europlus models were developed.
Woz is one of the greatest engineers of the 20th century, and the Apple II demonstrates his talent. After its 1977 debut, no other mass-market home computer offered color output until the Atari 400/800 line two years later. But his brilliance at simplifying things always straddles the line between optimized and overoptimized. The Disk II might be his greatest feat at doing more with less, while the video circuitry falls just into overoptimization, given the color fringing, NTSC dependence for color, and lack of lowercase. Integer BASIC is somewhere in the middle; great performance (especially given (or maybe because) Woz knew nothing about mainstream BASIC), but the code is so tightly written that it was easier for Apple to license Microsoft BASIC than to add floating-point code to Woz's work.
IWeldMelons
This is unnecessarily long non-answer to the parents question.
Woz is one of the greatest engineers of the 20th century, and the Apple II demonstrates his talent. After its 1977 debut, no other mass-market home computer offered color output until the Atari 400/800 line two years later. But his brilliance at simplifying things always straddles the line between optimized and overoptimized. The Disk II might be his greatest feat at doing more with less, while the video circuitry falls just into overoptimization, given the color fringing, NTSC dependence for color, and lack of lowercase. Integer BASIC is somewhere in the middle; great performance (especially given (or maybe because) Woz knew nothing about mainstream BASIC), but the code is so tightly written that it was easier for Apple to license Microsoft BASIC than to add floating-point code to Woz's work.