you know how when you set an image as your bg in gmail but like.
you can't see it because there's a massive block of ???SOME COLOUR??
don't @ me for colour choices btw i was testing.

anyway...

transparent now:
.nH {
    background-color: rgba(189, 189, 189, 0);
}

font colour of your emails:
.zE {
    color: #fff;
}

to be spicy, hover those:
.zE:hover {
    color: #fff;
    background-color: #84000085;
}

change the colours of read emails so you don't read them again:
.yO {
    background-color: #ff0000f5;
    color: #378a37;
    overflow: hidden;
}
.yO:hover {
    background-color: #db000036;
    color: #f00;
    overflow: hidden;
}

i forgot one, when you edit the inbox transparency it WILL ruin the
look of the emails when you click on them, sooooo:

.hx {
    background-color: #ffffffa8;
}

^ just change that colour/opacity to whatever you want