Color results are off

I bought this Pentax Z-50p Camera recently over the Internet and I really like it but the photos I take with it, well, the colors are off, in the sense that they are weak and dull. I use a photo editor to improve them but it is not enough. The camera is about 20 years old but it look as if it has been taken care. The picture is just not sharp enough even after tweaking them. Greens are a dull green as with the other colors. What should I do? Can this be fixed? Would a service help with this.

Phil