Change Kindergarten header colour

Hi, I’m a complete beginner compared to you guys but keen to learn.
I have a website https://www.potteriesactivekids.co.uk and would like to know how to do 3 things, I’ll post them one at a time as to not confuse matters.
Firstly, I’d like to change the colour of the font in the header on each page from the green that it is now to #00B050 for example, on the landing page ‘PAK’ the header ‘PAK’ has a finger pointing to it. It’s the colour of this finger and text that I’d like to change. Cheers