Header Colour not being applied

Hi,

My selected header colour is not being applied in my latest Perch install. The selected value is saved in the database, but is not being applied (header has background colour of #363636 which is the default).

Diagnostic report

Perch: 3.0.12, PHP: 5.6.31, MySQL: mysqlnd 5.0.11-dev - 20120503 - $Id: 76b08b24596e12d4553bd41fc93cccd5bac2fe7a $, with PDO
Server OS: Darwin, apache2handler
Installed apps: content (3.0.12), assets (3.0.12), categories (3.0.12)
App runtimes: <?php $apps_list = [ ];
PERCH_LOGINPATH: /admin
PERCH_PATH: /Users/mikeharrison/Google Drive/Client Work/247 Heating and Plumbing/Site/admin
PERCH_CORE: /Users/mikeharrison/Google Drive/Client Work/247 Heating and Plumbing/Site/admin/core
PERCH_RESFILEPATH: /Users/mikeharrison/Google Drive/Client Work/247 Heating and Plumbing/Site/admin/resources
Image manipulation: GD
PHP limits: Max upload 32M, Max POST 32M, Memory: 128M, Total max file upload: 32M
F1: 3b606135b33e6a102526838f4152a807
Resource folder writeable: Yes
HTTP_HOST: 247heating.mhd
DOCUMENT_ROOT: /Users/mikeharrison/Google Drive/Client Work/247 Heating and Plumbing/Site
REQUEST_URI: /admin/core/settings/diagnostics/
SCRIPT_NAME: /admin/core/settings/diagnostics/index.php