"This person has green eyes, small ears, and black hair."
Translation:Tenhle člověk má zelené oči, malé uši a černé vlasy.
Their primary meanings are the same as English "human" (or just "man" where it really means any "human" person) for člověk and "person" for osoba. They are not identical.
But Czech člověk tends to be used in contexts where English uses person.
You can't really translate things like the dawn of (hu)man, brotherhood of (hu)men with osoba as much as you can't use person there.
Why is it zelené and malé?
Since oko and ucho are Neuter, plural and in accusative i'd have thought it should be zelená and malá.
I know that there's something going on with nouns concerning both similar bodyparts making e.g. eyes to oči instead of oka..... does that maybe affect the adjectives, too?
Long time ago, it used to be dual. So jedno oko (singular) - dvě oči (dual) - tři oka (plural). All nouns had this special dual number.
But this feature as a systematic part of grammar has disappeared from Czech, having left a few traces. "Oči" is plural now (even if there are more than two, e.g. čtyři oči), but it changes its gender to feminine and has rather special declination. Same with uši, ruce, and nohy.