2 for text and background(primary & secondary colors). 1 accent color to highlight important elements(number 4 & buttons). And an OPTIONAL tertiary color to add a bit of personality(the hue slider).”
So, the article contradicts itself, saying that you need 3 colors.
Also, highlighting can be done by different means than color. You can use bold text, inverted video, a different font, blinking, more subtle animations, etc.
In fact, text and background need not be different colors. Varying brightness can be sufficient.
A nice example of all of that is the original Mac. It used two shades of gray (extremely dark aka ‘black’ and extremely light aka ‘white’), but many other monochrome interfaces also showed that two colors suffice.
I was going down the same path, about to suggest "quaternary" (also "quartary"), but the generated code reveals the rationale: there are 3 (not 4) in the ordered listing, plus an accent color. The explanation before the generator just happens to mention the accent color amidst mentioning the three ordered colors.
“You need 4 colors
2 for text and background(primary & secondary colors). 1 accent color to highlight important elements(number 4 & buttons). And an OPTIONAL tertiary color to add a bit of personality(the hue slider).”
So, the article contradicts itself, saying that you need 3 colors.
Also, highlighting can be done by different means than color. You can use bold text, inverted video, a different font, blinking, more subtle animations, etc.
In fact, text and background need not be different colors. Varying brightness can be sufficient.
A nice example of all of that is the original Mac. It used two shades of gray (extremely dark aka ‘black’ and extremely light aka ‘white’), but many other monochrome interfaces also showed that two colors suffice.