How Long does the water indicator on Samsung s6 take to change colour

[AC Question]

I dropped it in a tub of water and immediately took the phone out to dry it with a towel. I left it there for 20min without shutting down the phone. After 20min, I blow it with a fan for around 5min before shutting down the phone. When I take out the SIM card tray, I don't see any water indicator. I don't know if my phone is damaged by the water. What should I do now to check if my phone is damage?

 

[X1tymez]

Hi. You can check photo below.