To reset the ink levels, you need to wait for one of the colors on the printer to reach zero. This is usually signified by a red "X" on the printer or computer screen. Once you have this happening, all you will need to do is remove and replace the cartridges to reset the ink levels.
As for the colors not printing correctly, is this a refillable cartridge? IF so , make sure you've removed the air vent plug located opposite to where the sponge is located. That will need to be removed at all times in order to print correctly. If the air vent plug on a refillable cartridge is not removed, the prints will begin to turn faded/smudged/blank on the color.
IF this is for a CIS system, make sure the AIR FILTERS are installed . They are the plastic tips that go in on top of the CIS ink tank reservoirs. If there are not installed, the quality will also begin to fade . If the air filters ARE installed, make sure there is no ink trapped in the filters. Ink trapped inside the filters will make the prints restrict air passing into the cartridge. This will cause the ink quality to also fade.
To clean the air filters, you can place them inside a cup of warm/hot water for 10-15 min to clear the ink . You can tell if there is ink inside of them , because they are usually clear.
This video here will show you how to prime the cartridges if there are any existing air bubbles inside the lines. https://www.youtube.com/watch?v=2i2Ua5cnzsg
Let me know if you have any other questions. Thank you.