I assume we're talking bubblejet. Colour cartridges are generally smaller than the black because the black usually gets more use.
However, if the situation continues after you've applied new cartridges, there's a problem.
Printheads are not available generally though at a price (that probably exceeds that of a new printer) a repair tech could probably source and fit one.
To be frank, due to running cost and unreliability I abandoned bubble jet as soon as monochrome laser printers dipped under the $100 point.
And colour lasers are now approaching that region.