Eclipse has several spies, which can be used to introspect the state of the running workbench. Some are available by default, such as the Plug-in Spy and the Menu Spy, but the ones relating to styling have to be separately installed from a snapshot build site at http://download.eclipse.org/e4/snapshots/org.eclipse.e4.tools/latest/
Argentina
Australia
Austria
Belgium
Brazil
Bulgaria
Canada
Chile
Colombia
Cyprus
Czechia
Denmark
Ecuador
Egypt
Estonia
Finland
France
Germany
Great Britain
Greece
Hungary
India
Indonesia
Ireland
Italy
Japan
Latvia
Lithuania
Luxembourg
Malaysia
Malta
Mexico
Netherlands
New Zealand
Norway
Philippines
Poland
Portugal
Romania
Russia
Singapore
Slovakia
Slovenia
South Africa
South Korea
Spain
Sweden
Switzerland
Taiwan
Thailand
Turkey
Ukraine
United States