Bismillahir Rahmanir Rahim.
Assalamu 'alaikum wa rahmatullahi wa barakatuh.
To change colour from colour to black and white or from black and white to colour , follow the step by step guide below.
Step 1
Tap anywhere on screen to show the bottom menu and tap the Settings option
Step 2
Tap the indicated icon to change colour to black and white.
Step 3
Wait for a second for the colour of the page to change.
JazakAllah Khair