Thank you all, honestly it doesn't have to be Sigil based. I quite enjoy the Planescape universe and setting but I am preferably just wanting to play in a setting that is more typical D&D world but one that allows more cultural variances for humans outside of the typical European tropes of the your typical D&D setting, meaning my darkskinned Aasimar won't seem odd or out of place for the server setting. I don't want to disturb anyone's immersion. Also I'm more so looking to play the traveling good Samaritan classic type of Aasimar so Sigil's more enclosed city environment isn't really what I'm looking for. I'd like to be out and about in the countryside just saving people from monsters and such wandering around.
In a more open lore setting he would be a follower of what would be known as the God of Good Samaritans - The Great Father, basically your wandering Paladin that assists travelers, small villages and towns. The Great Father would be an NG god and Paladins of his order would take pilgrimages walking (or riding) the roads, narrow paths and trails of the world assisting travelers. Every place they would help they end up tying a golden scarf around a nearby tree,signpost,etc to the town indicating that area of habitation is under their protection. Your classic wandering hero/good samaritan trope but a gold flecked darkskinned Aasimar who wanders the roads singing or humming as he makes his way around the world on his pilgrimage. (Imagine the opening with Gandalf singing as he made his way into the Hobbit village in the first LOTR movie)
Your average Paladin of the "Order of the Wandering Hero" would look somewhat disheveled from constantly traveling, wear a gold scarf somewhere on their body and are not allowed to cut their facial hair or hair on their heads - an indicator of how long their pilgrimage is. Long ponytails, dreadlocks, etc would be the norm for these guys/ladies. Only after their pilgrimages are over and they have retired may they cut their hair (Their locks are preserved and kept in the Order's Hall of Wandering Heroes). Rangers would also be a part of this order and many of the Paladins would be mistaken more for a Ranger than your typical Paladin.
Thanks everyone for the suggestions! Such a warm community!