Using the WordPress theme customizer on WP-Admin > Appearance > Customize it is more than easy to change the main accent color of Elviria using the color picker.
Apart from the color you can use the customizer to upload your custom header image in seconds.
The possible color options are endless.
This theme is built for WPCasa WordPress Real Estate.
If you would like to use this design for your estate agency, go here to purchase the theme.