zitadel/internal/ui/login/static/resources/scripts/avatar.js

const avatars = document.getElementsByClassName('lgn-avatar');
for (let i = 0; i < avatars.length; i++) {
    const displayName = avatars[i].getAttribute('displayname');
    if (displayName) {
        const split = displayName.split(' ');
        if (split) {
            const initials = split[0].charAt(0) + (split[1] ? split[1].charAt(0) : '');
            if (initials) {
                avatars[i].getElementsByClassName('initials')[0].innerHTML = initials;
            }
        }

        const color = this.getColor(displayName);
        avatars[i].style.background = color;
        // set default white text instead of contrast text mode
        avatars[i].style.color = '#ffffff';
    }
}

function getColor(userName) {
    const colors = [
        'linear-gradient(40deg, #B44D51 30%, rgb(241,138,138))',
        'linear-gradient(40deg, #B75073 30%, rgb(234,96,143))',
        'linear-gradient(40deg, #84498E 30%, rgb(214,116,230))',
        'linear-gradient(40deg, #705998 30%, rgb(163,131,220))',
        'linear-gradient(40deg, #5C6598 30%, rgb(135,148,222))',
        'linear-gradient(40deg, #7F90D3 30%, rgb(181,196,247))',
        'linear-gradient(40deg, #3E93B9 30%, rgb(150,215,245))',
        'linear-gradient(40deg, #3494A0 30%, rgb(71,205,222))',
        'linear-gradient(40deg, #25716A 30%, rgb(58,185,173))',
        'linear-gradient(40deg, #427E41 30%, rgb(97,185,96))',
        'linear-gradient(40deg, #89A568 30%, rgb(176,212,133))',
        'linear-gradient(40deg, #90924D 30%, rgb(187,189,98))',
        'linear-gradient(40deg, #E2B032 30%, rgb(245,203,99))',
        'linear-gradient(40deg, #C97358 30%, rgb(245,148,118))',
        'linear-gradient(40deg, #6D5B54 30%, rgb(152,121,108))',
        'linear-gradient(40deg, #6B7980 30%, rgb(134,163,177))',
    ];

    let hash = 0;
    if (userName.length === 0) {
        return colors[hash];
    }
    for (let i = 0; i < userName.length; i++) {
        hash = userName.charCodeAt(i) + ((hash << 5) - hash);
        hash = hash & hash;
    }
    hash = ((hash % colors.length) + colors.length) % colors.length;
    return colors[hash];
}