Masonry paint (King's Lynn PE30)

I have replaced a window with a door & the ‘extra’ bit has been rendered & I need a small amount of masonry paint to paint the render. It will all be painted in the coming months so this is just to protect the render until I can get the whole house painted. Any colour would be lovely please, it is about 3’ x 2’ or 90cm x 50cm.
Many thanks 😊