@ PelesTears- If you are on a budget, and size does matter, look for a diamond with at least a medium blue fluorescence. A medium fluorescence can mask some of the color of a diamond. The fluorescence will make a diamond appear about one to two color grades whiter. A diamond with a color grade of J will appear to be an H or I.
You should also stick with a brilliant cut diamond, and a smaller table. An emerald cut 1 carat stone has a very large table, so you will see all of the color and flaws trapped in the stone. All of these characteristic combinations will allow you to purchase a larger stone with a very good to excellent cut for a cheaper price. The diamond will look great, but not cost you an arm and a leg.