Pearls don't change their color.
oxidation causes iron to change color. oxidation causes rust.
The level of melanin in the eye changes.
Herpes.
oxygen
Reagent strips change color by reacting with specific substances present in the sample being tested. This reaction causes a chemical change, resulting in a visible color change on the strip. The intensity of the color change can indicate the concentration of the target substance in the sample.
Paramagnetic color change in materials occurs when the material is exposed to a magnetic field. This causes the alignment of the material's magnetic moments, resulting in a change in its optical properties and color.
yes.cuz of the heat the sun causes on ur skin.
you would expect a color change in oil of wintergreen because it has an OH group added to the FeCl3 which causes a purple color
Perl is a programming language. Perl is an interpreted programming language. Perl is very useful for shell scripts, application programming, and web applications. Perl is quite easy to learn. Perl can be, but does not have to be, object-oriented. Perl was created by Larry Wall. Perl has probably the best implementation of regular expressions in existence.
It is caused by a bunch of broken blood vesseles, causing the color of a bruise to change.
the minerals change color due to the water around it
Both, for the bug to exhibit an external change (its color), there must first be an internal change that triggers the color change (its color). Thus, the internal change facilitates the external change. The predator is an external factor that causes an internal reaction (maybe it's fear) in the bug, that internal reaction then triggers an external factor which is the change in color. Just a personal opinion.