JSFiddle - React, Tailwind, and code Playground

HTML

<button id="btn:1:uniquenamehere">btn</button>
<button id="btn:2:uniquenamehere">btn</button>
<button id="btn:3:uniquenamehere">btn</button>
<button id="btn:4:uniquenamehere">btn</button>
<button id="btn:5:uniquenamehere">btn</button>

JavaScript

var elems = document.querySelectorAll('[id$="uniquenamehere"]');

for(var i = 0; i < elems.length; i++){
  elems[i].style.color = '#f00';   
}