Etymology of kaṇha / kāḷa ?

Dear all

recently, I came across the synonyms kaṇha and kāḷa.  I got the idea that these
two might be variant spellings or dialectal differences - retroflex ṇh and ḷ,
the latter between vowels here, seem to be very similar sounds.

Is there any basis to this understanding of mine?

Kind regards,
Florian