Colour schemes for Oracle SQL Developer

Color schemes

VS2010-Dark

Many thanks to Ozmoroz for providing clear instructions (Source):

Close SQL Developer. This is important. If you modify the scheme file while SQL Developer is open, your changes won't be saved.
Locate file dtcache.xml in the SQL Developer's settings directory. On my system it is located in directory C:\Users\sergey\AppData\Roaming\SQL Developer\system4.0.3.16.84\o.ide.12.1.3.2.41.140908.1359
Locate <schemeMap> tag inside dtcache.xml file. Insert the content of color scheme xml file inside <schemeMap> alongside the other colour schemes. Be careful not to break the XML.

Insert the contents of the color scheme xml after opening schemeMap tag (where I typed the comment 'Insert XML here'

Launch SQL Developer. Navigate to menu Tools->Preferences, then select item Code Editor -> PL/SQL Syntax Colours in the left pane.
Select the color scheme name in the "Scheme" drop down list on the top.