SCSS Custom Colors in Ionic

I want to know how i can add dynamic color hex code coming from backend services (The color will be selected by the user from dashboard).

How I can implement that hex color in the ionic app css?
Means if the user select color is DarkBlue then specific element in the app color changes to DarkBlue.

<link href="css/" rel="stylesheet">
<link href="css/style.css" rel="stylesheet">

I have tired SCSS but it didn’t work. Glup and other stuff is already added in the project and functioning properly.