When you inspect the element (I have the code from this example), you can notice than the color div is created after the text. So NO, you can't achieve what you want properly.
<div _ngcontent-c21="" class="example-ripple-container mat-elevation-z4 mat-ripple mat-ripple-unbounded" matripple="">
Click me
<div class="mat-ripple-element" style="left: -107.606px; top: -161.106px; height: 511.211px; width: 511.211px; background-color: rgba(255, 255, 0, 0.5); transition-duration: 400ms; transform: scale(1); opacity: 0;"></div>
</div>
BUT there is a hack to do that:
.mat-ripple-element{
z-index:-1 !important;
}
.mat-ripple{
z-index:50; // 50 for example
}