the Arabic من can be in the meaning of from and "of".
In English you are using 'of' mostly to define a thing by relating it to another thing.
But in Arabic we define words by simple putting them in order.
the proceeding one is defined by adding it to the following one
thus we can say
the color of the wall = لون السماء
notice that the الـ is attached to the 'sky' which is known by itself and we are defining which color by relating(addin) it to that known word.
the capital of Iraq عاصمة العراق
in advanced level of Arabic lessons you will find some references to "how the first word is pronounced".
for example لونُ السماء
or لونَِ السماء
this is to show weather that thing (which is defined this way) it, itself play the role of subject or object in the sentence.
The Arabic sentence conveys much information or details details in every single phoneme of it. in short you need not to replace 'of' with anything in Arabic.
so you can trace "of" and من in this light
But there are occasions when "of" is used in the meaning of "some"
in such cases you will need من
like :
sum of money مبلغ من المال
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