customize backgrounds on portfolio templates

src/registrar/assets/sass/_theme/_base.scss

@@ -33,10 +33,13 @@ body {
 }
 
 #wrapper.dashboard--portfolio {
-  background-color: color('gray-1');
   padding-top: units(4)!important;
 }
 
+#wrapper.dashboard--grey-1 {
+  background-color: color('gray-1');
+}
+
 
 .section--outlined {
   background-color: color('white');

src/registrar/templates/portfolio_base.html

@@ -1,8 +1,8 @@
 {% extends "base.html" %}
 
 {% block wrapper %}
-  <div id="wrapper" class="dashboard--portfolio">
-      {% block content %}
+  <div id="wrapper" class="{% block wrapper_class %}dashboard--portfolio{% endblock %}">
+    {% block content %}
         
         <main class="grid-container">
             {% if user.is_authenticated %}
@@ -26,10 +26,8 @@
             {% endif %}
         </main>
 
-      {% endblock %}
-
+      {% endblock content%}
     <div role="complementary">{% block complementary %}{% endblock %}</div>
-
     {% block content_bottom %}{% endblock %}
   </div>
 {% endblock wrapper %}

src/registrar/templates/portfolio_domains.html

@@ -4,6 +4,10 @@
 
 {% block title %} Domains | {% endblock %}
 
+{% block wrapper_class %}
+  {{ block.super }} dashboard--grey-1
+{% endblock %}
+
 {% block portfolio_content %}
 <div id="main-content">
     <h1 id="domains-header">Domains</h1>

src/registrar/templates/portfolio_requests.html

@@ -4,6 +4,10 @@
 
 {% block title %} Domain requests | {% endblock %}
 
+{% block wrapper_class %}
+  {{ block.super }} dashboard--grey-1
+{% endblock %}
+
 {% block portfolio_content %}
 <div id="main-content">
     <h1 id="domain-requests-header">Domain requests</h1>