I tried searching in the old comics to find classic Sonic brown eyes, but I don't know which comic.
I found this one in Sonic Universe 42 page 13
media.sonicscanf.org/comics/so…Elias's flashback of Elias trying to stop Sonic and Geoffrey argument.
It even say so in Pre-SGW Sonic's Bio:
sonic.wikia.com/wiki/Sonic_the…