In order to customize the colors and put the one which suits your project, you can easily do that in two steps explained below:
Step 1 - Change Color Variables in SCSS
All the sass variables related to colors could be found in the file {starter-template} / assets / scss / themes / default / _variables.scss
Now, you can change value of these variables as per your selected color palette.
NOTE: In case, you are working with default/ template then use the one of the specific theme you want:
{starter-template}/assets/scss/themes/dark-theme/_variables.scss
In case of dark theme.{starter-template}/assets/scss/themes/light-theme/_variables.scss
In case of light theme.{starter-template}/assets/scss/themes/semidark-theme/_variables.scss
In case of semi-dark theme.
Step 2 - Generate CSS files from SCSS
This step is to compile the changes we have made in SCSS files and generate the CSS version of those. For that, you can follow the Step-3 NPM Commands defined on Setup Drift topic.