It is completely okay. Diamonds can be very expensive and some people just don't have the budget for it. If you want a colorful stone on your ring, a colored diamond can be even more expensive than the classic colorless option. While diamonds are the most durable stone, there are other gemstones that are durable as well and you won't have to break the bank. Some gemstones can have symbolism that speaks to you. All that matter is that you are happy with your ring, at the end of the day.