White colour missing from colour picker?

Hi everybody!

In the latest update (January 2017?) of my free Acrobat reader for Android (I can't tell you which version as this info is not provided anymore), it seems Adobe has removed the white colour from the colour picker (in the paying version as well apparently), and it was the only colour I was extensively using as an eraser to hide unwanted elements, lines, shadows, spots... I'm sure it was usefull to lots of users. The wole app becomes pretty useless to me now. I can't believe they have done that! Did they recive tons of complaints against the presence of white colour? What's the added value?

Does anybody have a tip on how to get the white colour back, or an eraser?

Thanks a lot in advance and I wish you a nice, colourful day!