They appear to be standard size tubes, which means you should be able to get them from a hardware store or electrical supply store. They don't have to be the same, but I would toss the warm white, which is a very yellow light similar to incandescent. If you can try and find a tube with a high CRI, Colour Rendition Index, which will display colours better. The closer to 100 the better. It will be on the tube or package. Typically tubes in the 5000K to 6500K will give the most pleasing results and have high CRIs, although this is not always the case. You should expect to pay less for a tube bought in an hardware or electrical lighting outlet, than a tube specifically marketed for fish tanks.
Join a fish club. Don't have one in your area? Start one.