Hi, Tiialiina!
To do this, in the file style.css find this:
/* Data-tab (Ribbons)
-------------------------------------------------------------- */
#content .col01 .date-tab {
position: relative;
z-index: 1;
width: 20%;
float: left;
font-size: 1.5em;
font-weight: bold;
line-height: 70%;
margin: -5px 10px 10px -90px;
color: #000;
background-color: #A00B0B;
border-radius: 8px 1px 1px;
text-shadow: 0px 1px 2px #C53D3D;
-webkit-box-shadow: 0px 2px 4px #110303;
-moz-box-shadow: 0px 2px 4px #110303;
box-shadow: 0px 2px 4px #110303; }
#content .col01 .date-tab:before {
content: ' ';
position: absolute;
width: 40px;
height: 0;
left: -40px;
top: 30px;
border-radius: 0 0 10px;
border-width: 20px 10px;
border-style: solid;
border-color: #A00B0B #A00B0B #A00B0B transparent; }
#content .col01 .date-tab:after {
content: ' ';
position: absolute;
width: 0;
height: 0;
left: 0px;
top: 100%;
border-radius: 8px 0 0px;
border-width: 5px 10px;
border-style: solid;
border-color: #6D0404 #6D0404 transparent
transparent; }
#content .col01 .date-tab .month {
text-align:right;
display:block;
padding:6px 16px 6px 0;
font-size:70%; }
#content .col01 .date-tab .day {
text-align:right;
display:block;
padding:6px 16px 2px 0;
font-size:112%;
font-weight:bold; }
/* END-Data-tab (Ribbons) */
and replace to this (DARK GRAY):
/* Data-tab (Ribbons)
-------------------------------------------------------------- */
#content .col01 .date-tab {
position: relative;
z-index: 1;
width: 20%;
float: left;
font-size: 1.5em;
font-weight: bold;
line-height: 70%;
margin: -5px 10px 10px -90px;
color: #000;
background-color: #383535;
border-radius: 8px 1px 1px;
text-shadow: 0px 1px 2px #5B5555;
-webkit-box-shadow: 0px 2px 4px #110303;
-moz-box-shadow: 0px 2px 4px #110303;
box-shadow: 0px 2px 4px #110303; }
#content .col01 .date-tab:before {
content: ' ';
position: absolute;
width: 40px;
height: 0;
left: -40px;
top: 30px;
border-radius: 0 0 10px;
border-width: 20px 10px;
border-style: solid;
border-color: #383535 #383535 #383535 transparent; }
#content .col01 .date-tab:after {
content: ' ';
position: absolute;
width: 0;
height: 0;
left: 0px;
top: 100%;
border-radius: 8px 0 0px;
border-width: 5px 10px;
border-style: solid;
border-color: #1E1A1A #1E1A1A transparent transparent; }
#content .col01 .date-tab .month {
text-align:right;
display:block;
padding:6px 16px 6px 0;
font-size:70%; }
#content .col01 .date-tab .day {
text-align:right;
display:block;
padding:6px 16px 2px 0;
font-size:112%;
font-weight:bold; }
/* END-Data-tab (Ribbons) */
or replace to this (DARK BLUE):
/* Data-tab (Ribbons)
-------------------------------------------------------------- */
#content .col01 .date-tab {
position: relative;
z-index: 1;
width: 20%;
float: left;
font-size: 1.5em;
font-weight: bold;
line-height: 70%;
margin: -5px 10px 10px -90px;
color: #000;
background-color: #000328;
border-radius: 8px 1px 1px;
text-shadow: 0px 1px 2px #0C0158;
-webkit-box-shadow: 0px 2px 4px #110303;
-moz-box-shadow: 0px 2px 4px #110303;
box-shadow: 0px 2px 4px #110303; }
#content .col01 .date-tab:before {
content: ' ';
position: absolute;
width: 40px;
height: 0;
left: -40px;
top: 30px;
border-radius: 0 0 10px;
border-width: 20px 10px;
border-style: solid;
border-color: #000328 #000328 #000328 transparent; }
#content .col01 .date-tab:after {
content: ' ';
position: absolute;
width: 0;
height: 0;
left: 0px;
top: 100%;
border-radius: 8px 0 0px;
border-width: 5px 10px;
border-style: solid;
border-color: #000003 #000003 transparent transparent; }
#content .col01 .date-tab .month {
text-align:right;
display:block;
padding:6px 16px 6px 0;
font-size:70%; }
#content .col01 .date-tab .day {
text-align:right;
display:block;
padding:6px 16px 2px 0;
font-size:112%;
font-weight:bold; }
/* END-Data-tab (Ribbons) */
Over time, I’ll add an option to customizer to easily change the color of the red ribbon.