JSFiddle - React, Tailwind, and code Playground

HTML

<span class="test"><span style="color:green">Teste</span>:</span> Text<br><br>
<span class="test"><span style="color:green">Mais</span>:</span> Text<br><br>
<span class="test"><span style="color:green">Número</span>:</span> 250<br><br>
<span class="test"><span style="color:green">Teste</span>:</span> Text<br><br>
<span class="test"><span style="color:green">Mais</span>:</span> Text<br><br>
<span class="test"><span style="color:green">Número</span>:</span> 250<br><br>
<span class="test"><span style="color:green">Teste</span>:</span> Text<br><br>
<span class="test"><span style="color:green">Mais</span>:</span> Text<br><br>
<span class="test"><span style="color:green">Número</span>:</span> 250<br><br>

JavaScript

var rotulos = document.querySelectorAll('.test span'), rotulo;
var valores = [], valor, node;
for(var i=0; i<rotulos.length; i++) {
    rotulo = rotulos[i].textContent || rotulos[i].innerText;
    if(rotulo === 'Número') {
        node = rotulos[i].parentNode.nextSibling;
        valor = node.textContent || node.innerText;
        valores.push(Number(valor));
    }
}
console.log(valores);