MISSING BLACK CAT, TALLAGHT DUBLIN AREA

My MALE black cat, Ace went missing and has not been home since. He was seen in Glenshane, Tallaght Dublin 24 on a back garden wall and could not be caught. He is black but in the light/sun, his fur appears brown with stripes (otherwise he looks like a black cat when not in sun or light) He has a few grey hairs below his neck area He is only year old and not neutered yet as he was going to be but he went missing just before hand. He is not a big cat for his age and he is very much missed in the home. Any help would be appreciated, Thank You.