How can the main colour theme be changed? I know you can change colours for each text, header and footer bg and font but that does not change button background colours and widget backgrounds etc. I want to change the whole colour theme from aqua to maroon all at once.
You need to change the color manually from Appearance>>Color Settings
You can see options viz; Colors,Breadcumb Colors and Button Colors where you can easily change the sections to your desired color.
For instance; For Button; Go to Appearance>>Color Settings>>Button Colors and change to specific color you want.
or if you want to change the color for any other sections besides the ones in customizer you can also add custom css.