[Change color to white]

So I'm trying to change the blue areas on the garage of the below picture to white using Affinity Photo.  to match the rest of the garage and I've tried numerous different techniques I've learned from Youtube but white only turns the blue to gray.  Any advice/tips on how to match the blue areas to the white areas of the garage/house?

 

 

[Publisher (Mac) Crashing]

I have a document with about 25 pages and the program has been slow and crashes after only about 10 minutes of use.  Please advise.

[Publisher Keeps Crashing after Latest Update]

I'm having a similar issue.  Publisher (Mac) is slow and then crashes.  particularly when adding text and tables.  I need them to fix ASAP!