Hey @Roland_Alden! I think your best bet might be custom CSS. The post goes over where to put the CSS and how to grab the correct selector for your icon.
Here's an example:

#rt-table-table1 > div.rt-tbody > div:nth-child(1) > div > div:nth-child(5) > div > div > div > img {
opacity: 0.5
}
Let me know how this works for you!