refactor(admin-ui): Refactor header colour

packages/admin-ui/src/lib/core/src/components/app-shell/app-shell.component.scss

@@ -26,7 +26,7 @@
     align-items: center;
     justify-content: space-between;
     padding: calc(var(--space-unit) * 4);
-    background-color: var(--color-weight-70);
+    background-color: var(--page-header-color);
 }
 
 .main-nav-container {
@@ -83,13 +83,3 @@
     position: relative;
     margin-right: auto;
 }
-
-::ng-deep {
-    .header {
-        background-image: linear-gradient(
-            to right,
-            var(--color-header-gradient-from),
-            var(--color-header-gradient-to)
-        );
-    }
-}

packages/admin-ui/src/lib/core/src/shared/components/page-header/page-header.component.scss

@@ -1,5 +1,5 @@
 :host {
     display: block;
     border-bottom: 1px solid var(--color-weight-150);
-    background-color: var(--color-weight-70);
+    background-color: var(--page-header-color);
 }

packages/admin-ui/src/lib/static/styles/theme/default.scss

@@ -57,7 +57,6 @@
 
     --color-white: #fff;
     --color-black: #000;
-    --color-weight-70: hsl(0 0% 98%);
     --color-weight-100: hsl(0 0% 95%);
     --color-weight-125: hsl(0 0% 93%);
     --color-weight-150: hsl(0 0% 90%);
@@ -161,8 +160,7 @@
     --color-login-gradient-bottom: black;
 
     // header
-    --color-header-gradient-from: var(--color-primary-800);
-    --color-header-gradient-to: var(--color-primary-900);
+    --page-header-color: hsl(0 0% 98%);
 
     // Border radius
     --border-radius-sm: div(var(--clr-global-borderradius), 2);