<meta name="viewport" content="width=device-width,initial-scale=1">
<style>
div {
    width: 250px;
    height: 200px;
    position: relative;
}

.a {
    background-color: #895;
}

.b {
    background-color: #55f;
}

.button {
    position: absolute;
    width: 72px;
    height: 72px;
    left: calc(50% - 36px);
    top: calc(50% - 36px);
}

.background {
    position: absolute;
    width: 72px;
    height: 72px;
    -webkit-clip-path: circle(36px);
}

.a .background {
    background-color: rgb(159, 181, 85);
}

.b .background {
    background-color: rgb(113, 113, 255);
}

.glyph {
    -webkit-appearance: none;
    position: absolute;
    width: 72px;
    height: 72px;
    opacity: 0.6;
    background-image: url('data:image/png;base64,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');
    background-repeat: no-repeat;
    background-position: 50% 50%;
    background-size: 100% 100%;
}


</style>

<div class="a">
    <div class="button">
        <div class="background"></div>
        <div class="glyph"></div>
    </div>
</div>

<div class="b">
    <div class="button">
        <div class="background"></div>
        <div class="glyph"></div>
    </div>
</div>