Why in Black and White ?

On Friday night, when i reached home after work, i saw this envelop on my table. 

"Must be bills, to be paid, again..." i thought to myself. 

Truly, it is my mobile bills, from Singtel. 

And this month, they printed it in Black and White. (instead of the full coloured ones like previously.)  

I think they also trying to save Kaya  Gaia, and print in Black and White.

Or they ran out of colour inks. 

Did you receive your bills from Singtel in Black and White, this month, like me too ??