Logos changed to white

I have 43 png logos that I need changing to white png logos.

Can they all be made the same size to Max width 600, max length 400

Some logos have multiple colours and accents. I want the main part of the logo to be white and the remainder to be grey (#535353)

Also would like the same but (Main grey, accent colours white)

3 difficult examples provided. Can provide others too.