The Geez Fidel which was invented in Tigrai is still used through out Ethiopia. No one can be sure when it was introduced first but it is related to an ancient South Semitic language. Geez developed in the current state of Tigrai northern Ethiopia in the Horn of Africa. It is also used in Eritrea to some extent.
The highlighted alphabets have duplicate sound now days. They might have had different sound when they were created long time ago and lost their sound over time. The light green and blue highlighted alphabets have duplicate sound in Tigrigna. All highlighted alphabets including the ones that are duplicated in Tigrigna have duplicated sound in Amharic.