doc is not showing that you need css style also.

[MilkyWayGalaxyUser]

doc is not showing that you need css styling also. only JS and HTML which is wrong.
you need css styling also.

/* picker /
.color-picker {
background: rgba(255, 255, 255, 0.75);
padding: 10px;
border: 1px solid rgba(203, 203, 203, 0.6);
border-radius: 2px;
transition: all 300ms;
border-radius:20px;
position: fixed;
top: -5%;
min-width: 200px;
opacity: 0;
box-shadow: 0px 0px 4px rgba(0, 0, 0, 0.226);
left: 0px;
width: 100%;
z-index: 9999;
}
/ CIRCLE COLORS CSS*/
.color-picker > div {
width: 40px;
display: inline-block;
height: 40px;
margin: 5px;
border-radius: 100%;
opacity: 0.7;

}

.picker-wrapper {
padding: 20px;
}

.color-picker > div:hover {
opacity: 1;
}