html - How to update placeholder color using Javascript?

Question

I'm searching online and I didn't find anything. I'm trying to update the placeholder color of a textbox using javascript, but how can I do that? I have a color picker and the color is changing.

If I have something like this in my CSS, how can I update it?

::placeholder {
  color: red;
}

<input placeholder="placeholder" />

Answer 1

Use CSS variables. You can also target only the needed element

function update() {
  document.querySelector('input[type=text]').style.setProperty("--c", "blue");
}

::placeholder {
  color: var(--c, red);
}

<input type="text" placeholder="I will be blue">
<input type="number" placeholder="I will remain red">
<button onclick="update()">change</button>