The Verdict: Not eligible
You cannot claim Colombian nationality through your grandparent, because the parent who linked you to them died without registering as Colombian. Colombian nationality passes only from parent to child.
A child of a Colombian born abroad becomes Colombian by registering at a consulate or settling in Colombia. A parent who did neither in their lifetime was never Colombian, so there is no Colombian parent for you to register through. The Constitutional Court put it plainly in 2024 (ruling T-257 of 2024): nationality passes from parents to children, not from grandparents to grandchildren.
Check one thing first: if your parent ever lived in Colombia as an adult or held a Colombian identity card, they may have been Colombian after all, and the answer changes. The Registraduría can search for a record.
What works instead: our Skilled Migration, Retirement, Golden Visa and Digital Nomad quizzes for Colombia cover the residence visas, and after five years on a resident visa you could apply to naturalise.