Hi @wen,
Thanks for your reply. Buying the pro version will not sort my issue.
Like I said I have already created a child theme and know that I should be able to overwrite the function controlling the colours. I just don’t know how to do it.
Since I’m using a free theme, hiring a customizer is not in my budget.
So I guess I will have to keep on looking and learn more about functions or just hope someone will be kind enough to help me.