These (and many more) values are what you can change to customize the look of the HM web display. Install a CSS editor plugin for your browser and you can play around with the values live and then save the ones you like.
This is what I'm using:
#content { background:-webkit-gradient(linear, 100% 50%, 100% 100%, from(#000000), to(#322D15)); }
#contentframe { padding: 5px; }
#backimage { background: url(
https://i.imgur.com/JOKRVi2.jpg); }
#backoverlay { background: inherit; }
#probelist { background: rgba(0,0,0,0.3); }
#pn0 { color: #FFF; }
.pname { color: #FFF; font-size: 24pt; line-height: 16pt; display: inline-block; text-shadow:2px 2px 4px #000000 ; }
.dph { color: #ff0; font-size: 12pt; text-align: right; position: absolute; right: 0; bottom: 0; }
#fanl { color: #FFF; }
#fanc { opacity: 0.6; }
#fana { background: rgba(255,255,0,1); opacity: 1; }
#fancontainer { background:-webkit-gradient(linear, 100% 0%, 100% 100%, from(#000000), to(#322D15)) ; opacity: .7 ; border: 0px ; height: 20px; position: relative; }
#graph { height: 500px; width: 950px; margin: 8px auto 0px auto; }
#graph_overview { height: 100px; width: 920px; margin-left: auto; margin-right: auto; }