Bootstrap CSS classes wildcard

The CSS attribute contains selector can be used to achieve this:

.unique [class*=col]{...}

MDN is a useful reference site for CSS selectors. For reference, the attribute selectors are found here.

Pedro, what you're looking for is called attribute selector. In your particular case, you can use it like this:

.unique [class~=col] {color:red }

but you could also use this with more wide options like

[class*='col-']

to cover preceding white spaces.

Also, here you have the same documentation in Spanish