very strange problem in note 5 , what is fix?

[Uttam Kumar Khadka]

Today my note 5 ( marshmallow ) went to 7% battery level then i changed phone to ultra powersaving mode and then connected to my power bank. It was obvious my phone was in black and white mode . When it reached to 100% i switched it off as i had go outside. When i turned it on then it was black and white and i tried to off power saving mode but every appkication i clicked , the phone said it is unavailable. Even when i clicked setting it was limited to some options like wifi, brightness,mobile network etc only. There was no batterysaving options. I switched it off and on but same black and white. Even while booting the Samsung logo was black and white. So
My question is what is the problem and did any fren faced this problem ?
What is the fix except hard reset?
Thanks

 

[SingleAction]

It sounds like it might be your battery. Did you try a soft reset?

 

[Uttam Kumar Khadka]

It sounds like it might be your battery. Did you try a soft reset?

I have mention above that i my phone went to limited option.when i clicked the setting their were limited option like brightness etc. So how could i reset it.?

 

[anon(632115)]

A soft reset is where you reboot the device

 

[Uttam Kumar Khadka]

A soft reset is where you reboot the device

how to do soft reset?

 

[Uttam Kumar Khadka]

there Is no reset option on setting.

 

[anon(632115)]

Just turn it off and turn it back on

 

[Uttam Kumar Khadka]

Just turn it off and turn it back on

Did many times.. Same result