Either you need a word that's not English or the starting letter is wrong. There are many words for prison, but the ones with four letters is jail, brig, or the slang stir.
A 4 letter word starting with A that's a color is aqua.
icon, itch, into, isle
able
There are none. Not even a 3 letter word
Brit
jail
A four letter word starting with J is jump or joke.
KnowKnotKneeKnewKeepKeptKeelKeenKelpKilnKindKite
A 4 letter word starting with A that's a color is aqua.
icon, itch, into, isle
teal
RingRangRollRats
able
Anna
aver
goalgoatgodsgoesgoldgolfgonegonggoodgoongown
Seta is a 4-letter word for hair or bristle starting with S.