Being colorblind myself I always found it hard to use WhatsApp and differentiate whether my messages had been read or not.

So this

and this

look 90% the same to me at first sight (if you're also having trouble you might want to do a colorblind test). If I focus and get closer to the screen I'd be able to differentiate them, but why not make it more noticeable at a glance?

So I decided to build a browser extension that provides an easier way for the colorblind to identify WhatsApp Web message delivery status (sadly we can't modify the native apps though). This extension would simply make blue double-tick images a full round circle instead (for chat messages as well as those in the sidebar).

All it took was a bit of CSS:

span[data-icon="status-dblcheck-ack"] svg,
span[data-icon="msg-dblcheck-ack"] svg {
    background: rgb(79, 195, 247);
    border-radius: 100%;
}

span[data-icon="status-dblcheck-ack"] svg {
    width: 14px;
    height: 14px;
    margin-top: 2px;
}

span[data-icon="msg-dblcheck-ack"] svg {
    width: 10px;
    height: 10px;
    margin-top: 3px;
}

Ta da!

Download for Firefox or Chrome