Brian here from the Shopify support team :)
I can show you how to do so - Just follow these steps:
- In your Admin, go to Online Store > Themes > Beside the blue Customize theme button, click the button with the three small dots and then choose this option "Edit HTML/CSS".
- In the Assets folder, choose the theme.scss.liquid file.
- Search for line 2519, and you will see the variable "background-color:" - http://take.ms/FMXIH. Change that color to what you want, and you will be good to go. (Use a hexadecimal value for the color - Example: #FF0000 being red).
This will help you out, and if you need more guidance with this, just reply to my answer :)
thanks a lot but not the entire drop down is not the colour i want it to be. please could you help me and make the text on the header and the dropdowns white?