I would also say silvers, or a sunset blusher mixed with zebra .. DEF turn your flash OFF. and just use the tank lights , and maybye a bright time of day where you will have some light behind you as well . better pictures will help. but all in all I would still guess silvers . I just see the gold color in the top fin and heads that are in my sunset blushers, and mine the bodys are white. HTH and GL !! IMO < no gravel would not bother a fish . I would belive they are stressed from you chasing them around with that flash !! LOL ~~ try to getthem off gaurd and use the cam with no flash on, so it dosent wash thier color out. very pretty fish you have there ethier way 
