can i personalise my calendars to look like it want??

I want all of my apps products calendar to look the same.. for example

my mac is okay but i would prefer to change the colours etc..

my phone doesn't have boxes around the dates which i hate!

my iPad weekend colours aren't dark enough...

i want to use my diary more full time and step away rom my paper one but i want to make them look like i want them too.. thanks for your help!