Editing Paint (section)

==Color changing==
Various technologies exist for making paints that change color. [[Thermochromic ink]] and coatings contain materials that change conformation when heat is applied or removed, and so they change color. [[Liquid crystal]]s have been used in such paints, such as in the thermometer strips and tapes used in aquaria and novelty/promotional thermal cups and straws.

[[Photochromism|Photochromic]] materials are used to make eyeglasses and other products. Similar to thermochromic molecules, photochromic molecules change conformation when light energy is applied or removed, and so they change color.

Color-changing paints can also be made by adding halochromic compounds or other organic pigments. One patent<ref>{{cite web|last=Bramley|first=Christopher Sinjin|title=Colour changing paint|url=http://www.freepatentsonline.com/EP1400574A1.pdf|work=European Patent Application EP1400574|publisher=European Patent Office}}</ref>  cites use of these indicators for wall coating applications for light-colored paints. When the paint is wet it is pink in color but upon drying it regains its original white color. As cited in patent, this property of the paint enabled two or more coats to be applied on a wall properly and evenly. The previous coats having dried would be white whereas the new wet coat would be distinctly pink. Ashland Inc. introduced foundry refractory coatings with similar principle in 2005<ref>{{cite news|title=Dramatic color change featured|url=http://www.newmaterials.com/Customisation/News/General/General/Dramatic_color_change_featured_in_Ashlands_VELVAPLAST_ZW_FDI_refractory.asp|newspaper=New Materials International|access-date=2011-11-03|archive-url=https://web.archive.org/web/20120425132654/http://www.newmaterials.com/Customisation/News/General/General/Dramatic_color_change_featured_in_Ashlands_VELVAPLAST_ZW_FDI_refractory.asp|archive-date=2012-04-25|url-status=dead}}</ref><ref>{{cite web|last=Horvath|first=Lee|title=Coatings Go Beyond Appearance to Provide Quality Control|url=http://www.foundrymag.com/feature/feature/77970/|work=Foundry Technology|publisher=Foundry Management & Technology}}</ref> for use in foundries.

Electrochromic paints change color in response to an applied electric current. Car manufacturer [[Nissan]] has been reportedly working on an electrochromic paint, based on particles of [[paramagnetism|paramagnetic]] [[iron oxide]]. When subjected to an electromagnetic field the paramagnetic particles change spacing, modifying their color and reflective properties. The electromagnetic field would be formed using the conductive metal of the car body.<ref>{{Cite web |url=http://www.dailytech.com/Nissan+Develops+Color+Changing+Paint+for+Vehicles/article9611.htm |title=DailyTech - Nissan Develops Color Changing Paint for Vehicles<!-- Bot generated title --> |access-date=2008-03-19 |archive-url=https://web.archive.org/web/20110708222033/http://www.dailytech.com/Nissan+Develops+Color+Changing+Paint+for+Vehicles/article9611.htm |archive-date=2011-07-08 |url-status=dead }}</ref> Electrochromic paints can be applied to plastic substrates as well, using a different coating chemistry. The technology involves using special dyes that change conformation when an electric current is applied across the film itself. This new technology has been used to achieve glare protection at the touch of a button in passenger airplane windows.

Color can also change depending on viewing angle, using [[iridescence]], for example, in [[ChromaFlair]].