update color theme for heatmap (#8709)

Signed-off-by: May <themaymeow@gmail.com>

public/css/index.css

@@ -212,11 +212,11 @@ footer .ui.left,footer .ui.right{line-height:40px}
 }
 #user-heatmap .total-contributions{text-align:left;font-weight:500;margin-top:0}
 .heatmap-color-0{background-color:#f4f4f4}
-.heatmap-color-1{background-color:#d7e5db}
-.heatmap-color-2{background-color:#adc7ab}
-.heatmap-color-3{background-color:#83a87b}
-.heatmap-color-4{background-color:#598a4b}
-.heatmap-color-5{background-color:#2f6b1b}
+.heatmap-color-1{background-color:#d8efbf}
+.heatmap-color-2{background-color:#9fdb81}
+.heatmap-color-3{background-color:#66c74b}
+.heatmap-color-4{background-color:#609926}
+.heatmap-color-5{background-color:#025900}
 .archived-icon{color:#b3b3b3!important}
 .oauth2-authorize-application-box{margin-top:3em!important}
 .ui.tabular.menu .item{color:rgba(0,0,0,.5)}

public/less/_base.less

@@ -894,23 +894,23 @@ footer {
 }
 
 .heatmap-color-1 {
-    background-color: #d7e5db;
+    background-color: #d8efbf;
 }
 
 .heatmap-color-2 {
-    background-color: #adc7ab;
+    background-color: #9fdb81;
 }
 
 .heatmap-color-3 {
-    background-color: #83a87b;
+    background-color: #66c74b;
 }
 
 .heatmap-color-4 {
-    background-color: #598a4b;
+    background-color: #609926;
 }
 
 .heatmap-color-5 {
-    background-color: #2f6b1b;
+    background-color: #025900;
 }
 
 .archived-icon {