You Do Need power plug adapter while traveling from Côte d'Ivoire (Ivory Coast) to Sri Lanka.

Here is Why You Need An Adapter

The outlet and plug type used in Sri Lanka is G and in Côte d'Ivoire (Ivory Coast) are C and E. This is how they look like.

Côte d'Ivoire (Ivory Coast)

In Côte d'Ivoire (Ivory Coast), outlets of type C and E are in use.

Type C

Type E

Sri Lanka

In Sri Lanka, outlets of type G are in use.

Type G