How can i change Aegaeus theme header menu colour, font, background

Please, how can i change the Header menu default appearance such as
1. Upper case fonts to Sentence case
2. text Font colour and lines colour from black to white
3. Menu bar background colour from white(or transparent) to red (or custom red texture colour)
see attached illustration.

and also the hover colour and dropdown text and colours,
But most importantly, to change the menu bar colour, font colour and Case.