flushing

How long should i flush to get colour change in leaves??

What on earth makes you think flushing will make the leaves change color?
The leaves will eventually change color as they run out of nutes, but flushing will not by itself make the leaves change.

I should of been more clear sorry

I mean at the end off flowering. I flushed at the end of my last grow but they were still very green when i pulled them.
I just wanna kno how long to flush for roughly to get rid of nutes from soil so the start to lose there green nd start to yellow

Do you not lower the nutes the further you get down flowering ?

No dee (only lower nutes if i get burn)

Just wanna kno if i should give a 10 day 14 day or whatever flushing at the end

Simply stop feeding four weeks out. Address PKCaMg defs only as they occur. That would be what I would do. The soil, being an ion reservoir, will taper the nutes for you. cn