So I\'m using the Bootstrap Customize and Download page to generate a version of the Bootstrap files with custom colors. I got the idea that I wanted to add some other colors (e
You can't add more LESS variables with the custom download tool. You can only redefine the values of the existing variables. Upon download, the tool compiles with those set variables but since you don't get the LESS files, you won't be able to add more variables afterwards, like @purpleLight you mentioned.
If you want to extend Bootstrap with more LESS variables, you have to download the full source and compile your css from the included LESS files. There's a file variables.less
in the less/
folder where can add your @purpleLight.