why does a curry stain on white cloth becomes reddish-brown soap is scrubbed over it n then it turns yellow - Science - Acids Bases and Salts

Question

why does a curry stain on white cloth becomes reddish-brown soap
is scrubbed over it n then it turns yellow again if washed with
plenty of water ????

Ahmed Nihal Noufel · Accepted Answer

The curry might contain turmeric powder which is an indicator of
acids and bases
Soap being basic in nature turns the colour of the turmeric from
yellow to reddish-brown
After washing with lots of water the soap is removed and the
turmeric returns to its yellow colour

why does a curry stain on white cloth becomes reddish-brown soap is scrubbed over it n then it turns yellow again if washed with plenty of water ????