(feat): added background overlay colour

src/app/modules/pro/channel/channel.component.scss

 m-pro--channel {
- display: block;
- background: none no-repeat center fixed;
- background-size: cover;
-
  --primary-color: #4690df;
  --plain-background-color: #ffffff;
  --transparent-background-color: #ffffffa0;
  --text-color: #000000;
+
+ display: block;
+ background: none no-repeat center fixed;
+ background-size: cover;
+ background-blend-mode: overlay;
+ background-color: var(--transparent-background-color);
 }
 
 .m-pro--channel {
@@ -34,7 +36,7 @@ m-pro--channel {
 
  .m-proChannelTopbar__logo:focus {
  outline: none;
-  }
+ }
 
  & > * {
  padding: 0 16px 0 0;
@@ -42,7 +44,7 @@ m-pro--channel {
 
  .m-proChannelTopbar__SearchBox {
  margin: 0 16px;
- 
+
  @media screen and (max-width: 1081px) {
  flex-grow: 1;
  max-width: 300px;
@@ -76,7 +78,7 @@ m-pro--channel {
  color: themed($m-black);
  }
  }
- 
+
  input {
  height: 32px;
  border-radius: 18px;
@@ -95,7 +97,7 @@ m-pro--channel {
  }
  }
 
- 
+
  }
 
  .m-proChannelTopbar_menu.m-dropdown {