What is produced when a base reacts with water?

Hydroxide ions.

Explanation:When base reacts with water they form hydroxide ion.For example, NH₃      +    H₂O   >      NH₄⁺       +        OH⁻

                        (Ammonia)     (Water)           (Ammonium)    (Hydroxide ion).

In case of strong and week base, generally weak bases partially reacts with water to produce hydroxide ions. Whereas strong base completely reacts with water to produce hydroxide ions  And the reaction between a strong acid and a strong base produces salt and water and reaction is called neutralization reaction as both acid and base get neutralized.

Result: On reaction of base with water gives hydroxide ion.

Green is technically every other color but green but the other wavelengths of the other colors get absorbed by the object and the wavelength of the color green gets reflected