Add a small amount of potassium chlorate to conc. HCl. You get a very intensely colored yellow gas, ClO2.
However, do not use more than 100 mg of KClO3. DO NOT SCALE UP!!!
I did this nice experiment and put it on my website:
http://woelen.scheikunde.net/science/chem/exps/clo2/index.htmlWith potassium permanganate, you can make a so-called chemical chameleon:
Dissolve a very small amount in 100 ml of water, with quite some sugar and some sodium hydroxide dissolved in it. Watch the slow change of colors (purple, blue, green, red, brown, yellow). It is fascinating to see this. Do not add too much KMnO4. its color is very intense and if the color is too intense, then it all looks black.
H2O2 and KMnO4 can be used to make oxygen.
Adding a few drops of H2O2-solution to a deep purple acidified solution of KMnO4 makes it colorless at once.
The other oxidizers hardly are interesting outside the pyro-world. In aqueous solution they are very inert. Barium peroxide makes just H2O2 with milky barium hydroxide solution, then I simply prefer H2O2.
So, only chlorate and permanganate are interesting outside the pyro-stuff.
For the metals, zinc and iron are quite interesing outside pyro, but with this limited set of chems, there is not that much you can do.
With HCl you can make hydrogen gas from zinc powder and magnesium.