playing with colours with a theme

Hello,

I am using the ajaira theme

This theme uses black text, white, grey/gray for footer.

I would like to try out different colours/colors

Would i be right in saying that I could use a plug in or locate the hex codes referring to the colours/colors and altering to suit ?

I tried a plug in ‘ elegant themes ‘ but I did not like it much.

The theme appearance sidebar tool only changes header & background colours/colors, not the website text.

Any suggestions on plug ins for playing with colours or should I leave the colours as is ? Does SEO prefer staid colours/color schemes ?

https://www.louisawade.co.uk is the site.

Thanks for any tips