1. Colors make up our world.

2. Our world is made up by colors.
3. Our world is made up of colors.

(What is the passive form of the active form #1? Is it #2 or #3? Are both grammatical?)

4. Is two-word verb composed of a verb and an adverb? What about a verb and a preposition? Can it be also called a two-word verb?)

coulours make up our world

Passive would be - Our world is made of colors.

#3 would be the grammatical sentence.

The passive form of the active sentence "Colors make up our world" is "Our world is made up of colors." Both sentences #2 and #3 are grammatical and convey the same meaning, but sentence #3 is more commonly used and preferred.

A two-word verb consists of a verb and either an adverb or a preposition. When a verb is combined with an adverb, it is called a phrasal verb (e.g., "kick off" or "take up"). When a verb is combined with a preposition, it is called a prepositional verb (e.g., "look after" or "put up with").

So, a two-word verb can consist of a verb and an adverb or a verb and a preposition.