copper sulphate
Cobalt
blue
glass inner colur is blue because silicon gel is used for that one
I think "Blue" not sure though
Cobalt oxide is commonly used to give glass a blue color. When added to the glass mixture, cobalt oxide imparts a deep blue hue due to its strong light-absorbing properties.
Sea is actually not blue its transprent.If you take some water in a transprent glass its transprent.there actually a blue pigment present in there.The blue you see (haha) is the color of the reflected sky above itsunlight have 7 colour .when the sunlight enter in water some of colour will reflaction from water but blue colour is not reflactiol all some of colour will be left in water sothat seawater looking blue.
blue
Can't say why or why not, because it sin't a reaction at all! Blue is a color, thus a physical substance(s) property
Purple is a cold colour.. and my favourite!
The colour blue is a primary colour and therefore cannot be made by any other colour.
The sky is blue because as light travels through our atmosphere the higher frequencies (namely the blues) of it are more readily absorbed by the gas molecules in the atmosphere. These molecules then release that colour in different directions, giving the sky it's blue colour. The same goes for the sea, the seas blue colour is also caused by refraction and the scattering of light.
Quartz, Glass, and other materials are mixed together to make the clay-substance, which is then fired at a low heat to harden and creature blue pottery.