[FIX] web: better project kanban_status inactive color

- Use a lighter color so that the red and green ones are more visible
- Use the same color for the column progressbar's inactive state

addons/web/static/src/less/kanban_column_progressbar.less

@@ -55,7 +55,7 @@
         width: 76%;
         height: @font-size-base;
         margin-bottom: 0;
-        background: fade(black, 7%);
+        background-color: @gray-lighter-dark;
         box-shadow: none;
 
         .progress-bar {

addons/web/static/src/less/views.less

@@ -35,7 +35,7 @@
     border-radius: 6px;
     vertical-align: middle;
 
-    background-color: @odoo-brand-secondary;
+    background-color: @gray-lighter-dark;
 
     &.o_status_green {
         background-color: @brand-success;