Changing the parameter name to style_nav_header_background

Also making it to modify the background css property instead of
background-color

Signed-off-by: Gergely Csatari <[email protected]>

Author: CsatariGergely

sphinx_rtd_theme/layout.html

@@ -108,7 +108,7 @@
     {# SIDE NAV, TOGGLES ON MOBILE #}
     <nav data-toggle="wy-nav-shift" class="wy-nav-side">
       <div class="wy-side-scroll">
-        <div class="wy-side-nav-search" {% if theme_nav_header_background_color %} style="background-color: {{theme_nav_header_background_color}}" {% endif %}>
+        <div class="wy-side-nav-search" {% if theme_style_nav_header_background %} style="background: {{theme_style_nav_header_background}}" {% endif %}>
           {% block sidebartitle %}
 
           {% if logo and theme_logo_only %}

sphinx_rtd_theme/theme.conf

@@ -10,9 +10,9 @@ collapse_navigation = True
 sticky_navigation = True
 navigation_depth = 4
 includehidden = True
-nav_header_background_color = 
-titles_only = 
-logo_only = 
+titles_only =
+logo_only =
 display_version = True
 prev_next_buttons_location = bottom
 style_external_links = False
+style_nav_header_background =