[Bajo]

I've been searching around the net for a list of colours of chemicals, colour change during reactions etc. but till now, i still havn't found any list like that. Is it possible that someone could compile a list like that please? It would be a great help to many of us. Thank you.

[Alberto_Kravina]

Well, a very good thing that you should know is that many transition metal salts have caracteristic colours. Copper(II) ions have a blue-green color, Iron(II)salts a pale-green color, Iron(III) has a characteristic brown-red color, Chromium(III) salts are dark-green, Manganese(II) has a pink-white color, anhydrous Co(II)salts are pink and hydrous Co(II) salts are blue, Ni(II) has a green color....and so on....some other metals have other colors (I think that Ir has a nice red color, but check me on this.)

Another example are indicators...but as Mitch said there are billions of examples, please be a bit more specific!

[Mitch]

I hope you are jokeing. There are millions and millions of chemicals that could be reacted together in near infinite amount of  combinations at a whole range of temperatures.

[jdurg]

Well, a very good thing that you should know is that many transition metal salts have caracteristic colours. Copper(II) ions have a blue-green color, Iron(II)salts a pale-green color, Iron(III) has a characteristic brown-red color, Chromium(III) salts are dark-green, Manganese(II) has a pink-white color, anhydrous Co(II)salts are pink and hydrous Co(II) salts are blue, Ni(II) has a green color....and so on....some other metals have other colors (I think that Ir has a nice red color, but check me on this.)

Another example are indicators...but as Mitch said there are billions of examples, please be a bit more specific!

I think Ir does have a red salt, but Rhodium Chloride is most famously known for being a Rose Red color.  (Hence how it got its name "Rhodium" from the Greek "Rodon" which means "rose").

[Alberto_Kravina]

I think Ir does have a red salt, but Rhodium Chloride is most famously known for being a Rose Red color.  (Hence how it got its name "Rhodium" from the Greek "Rodon" which means "rose").

True! Other heavy metal salts such as Os, Au, W and so on have really cool colors (e.g. WC (Tungsten carbide, not a restroom ) has a shiny gold color) . Mo-salts have a deep blue color. Insoluble Hg²⁺ and Hg₂²⁺ are also nicely colored, although they are kind of toxic (e.g. Hg₂I₂ has a deep olive green color.)
But as I said before there are thousands of millions of possibilities...

[qlabel]

wow! a compound called WC..