Discolored Teeth

Hi mommies, Anyone here na nagdiscolored yung teeth ni baby.Ano po ginawa nyo? 1yr and 5months si baby pero yung upper teeth nya nagkakaroon ng parang color gray. According kay Google baking soda + drop of water, etc. might help pero hesitant akong gamitin kasi hindi pa sya marunong mag spit nang water kapag nagtoothbrush.I tried na basain yung clean cloth ng warm water then ikuskos sa teeth nya pero wala akong nakikitang changes. Before nagkaroon then ng stain yung teeth nya which is color yellow pero natatanggal nong tinigil ni pedia yung ferlin (vit) nya at kinukuskos ko ng clean cloth lang. Now yung vit nya ay anemifer, pedzinc and cherifer (all are drops and prescribed by her pedia).And colgate 0-2 years yung ginagamit nya pong toothpaste. Thanks! Stay safe & healthy po tayo☺️