Right now what blueprint's main css file has some classes like pt-intent-primary, pt-intent-success, pt-intent-warning; etc. i want to change the default colors of some of these classes. Should i import its source .scss file in my code(if Yes How?) or should i build separately a .css file from .scss file given and then use it.
This Github issue thread provides some good information about how to customize Blueprint's colors. In short, you should import blueprint's Sass source after changing all the color variables you need.
$pt-intent-primary: blue;
@import "~@blueprintjs/core/src/blueprint.scss";