This is intentional because the colors are meant to replicate the effect of analog ink on paper. Ink on paper is not emissive the way that LCD/OLED screens are,

This is intentional because the colors are meant to replicate the effect of analog ink on paper. Ink on paper is not emissive the way that LCD/OLED screens are, so I have strayed away from colors that are only possible on screens. That said there are a million other color schemes out there :)