Colours as diptotes

[Taalibah]

In lesson 16 (Book 2) it says in the key that both masculine and feminine forms of colours are diptotes. Diptotes don't get kasrah.

How come that in exercise 7, line 4, the answer is: bi-l-qalami -l-azraqi?

I would have thought: bi-l-qalami -l-azraqa (with fathah)

Is it because it comes in definite form?

[mmp_31]

Originally Posted by Taalibah

In lesson 16 (Book 2) it says in the key that both masculine and feminine forms of colours are diptotes. Diptotes don't get kasrah.

How come that in exercise 7, line 4, the answer is: bi-l-qalami -l-azraqi?

I would have thought: bi-l-qalami -l-azraqa (with fathah)

Is it because it comes in definite form?

As salaamu alaikum

What you say is correct, when it becomes definite (معرفة) then from diptote its turns to triptote.