You Do Need power plug adapter while traveling from Oman to Canary Islands.

Here is Why You Need An Adapter

The outlet and plug type used in Canary Islands are C, E and F and in Oman is G. This is how they look like.

Oman

In Oman, outlets of type G are in use.

Type G

Canary Islands

In Canary Islands, outlets of type C, E and F are in use.

Type C

Type E

Type F