Workbench 2.0 was released in 1990 and introduced a lot of improvements and major advances to the GUI of the overall Amiga operating system. The harsh blue and orange colour scheme was replaced with a much easier on the eye grey and light blue with 3D aspect in the border of the windows. The Workbench was no longer tied to the 640×256 (PAL) or 640×200 (NTSC) display modes, and much of the system was improved with an eye to making future expansion easier. For the first time, a standardised "look and feel" was added. This was done by creating the "Amiga Style Guide", and including libraries and software which assisted developers in making conformant software. Technologies included the GUI element creation library "gadtools", the software installation scripting language "Installer", and the "AmigaGuide" hypertext help system.