Turmeric stains on white clothes, when washed with soap, turn red. Why?

A turmeric stain on Chandana's white saree turned red when it is washed with soap. This is because soap solution is

(A) Dye does not absorb evenly on cloth washed with soap using hard water. (R) Insoluble calcium and magnesium soaps precipitate adheres on to the fibre of the cloth as gummy mass.

Is there any advantage of washing clothes with warm water than cold water? Why?

Padma took a little sodium hydroxide in a beaker and dipped a red litmus paper into it. She observed red litmus paper turned blue. She took dilute hydrochloric acid in the same beaker and dipped a blue litmus paper into it. The blue litmus paper did not turn red. Why ?

When turmeric is added with lime water it turns in to colour

If a white sheet of paper is stained with oil, the paper turns transparent. Why ?

People use a variety of methods to wash clothes. Usually after adding the soap, they ‘beat’ the clothes on a stone, or beat it with a paddle, scrub with a brush or the mixture is agitated in a washing machine. Why is agitation necessary to get clean clothes?