What are the description of the possible problems and solutions of finding a large number of small green insects on the leaves of your plant and the leaves are beginning to turn a pale green color?

most probably the plants are being attacked and eaten by the insects. if they are small and green they could be aphids (although "small and green" is not really a good enough description to determine what the pest is).

if the leaves are turning pale green and do no show any signs of being visibly eaten (such as by a Caterpillar, then the chances are the insects are "sap sucking". this means that the insects insert their mouth-parts into the plant (like a hypodermic syringe) and suck the sap from the plant.

to remedy the problem the insects have to be removed; this can be done manually (by picking them off), by spraying the plant with water to dislodge the insects or by applying a chemical (or organic) pesticide to kill the insects.

in most instances the damage caused by these types of insects is cosmetic and will simply disappear with time, or as the leave falls off.