I am building a web application where I have set my default color to navy blue using css. But when i added the twitter bootstrap css\'s in my page I did not find my navy blue co
Bootstrap 4 provides standard methods for this, fully described here: https://getbootstrap.com/docs/4.3/getting-started/theming
Eg. you can override defaults simply by setting variables in the SASS file, where you import bootstrap. An example from the docs (which also answers the question):
// Your variable overrides
$body-bg: #000;
$body-color: #111;
// Bootstrap and its default variables
@import "../node_modules/bootstrap/scss/bootstrap";