One other cute side note. It looks like all passports seem to span the colors of the rainbow!...save yellow. Gold seems to be the standard color of the type/designs, so I suppose yellow or orange[0] as backgrounds are out.
Most have dignified, darker tones. Singapore and Switzerland have the brightest backgrounds of brilliant red while a few have pale but not over-saturated greens (Niger, Guinea, Saudi Arabia). Actually Fiji has quite a cyan passport too.
[0] The red Singapore passport comes close to orange, although that might just be the way they scanned it.
For what it's worth, I know that the British emergency passport is pretty close to yellow - It seems to look more beige on the internet than I remember it though.
Most have dignified, darker tones. Singapore and Switzerland have the brightest backgrounds of brilliant red while a few have pale but not over-saturated greens (Niger, Guinea, Saudi Arabia). Actually Fiji has quite a cyan passport too.
[0] The red Singapore passport comes close to orange, although that might just be the way they scanned it.