Finding your own palette of colors is an ongoing process, with frequent changes involved. There are many colors out there and it can be overwhelming to choose what to work with. I actually have three heaping bags of oil colors that I've accumulated over the years; I have used and studied all of them in an effort to counteract my colorblindness. And many of them I have had on my palette at one point or other. Many of my palettes were also inspired by artists of the past.
When I admire an artist, I usually begin by studying what colors they use. And then the natural connection is to believe that using their colors will somehow enable me to paint as well as them. This is completely wrong and often times will impact your painting negatively because you are blindly using a pigment without learning the properties of the pigment. The artist whom you respect probably chose that palette because they tried many colors and learned about each color before using them.
The best way to prevent this idol worship is to strip away the colors to a very basic palette. You truly only need a handful of colors to complete a painting. Being colorblind, I am a strong believe in the power of value over anything else; your basic palette should have a wide value range.
A good basic palette to begin with is:
-Cadmium Yellow Light
-Cadmium Red (Or Vermillion)
I can definitively say that these colors are essentials to any palette. I use a fairly basic palette myself, but I will suggest that you try and figure out what colors you NEED instead of what colors you THINK you need. I recently painted a cat's eye that was a pale yellow color and I realized that I needed naples yellow to achieve the value and effect. I normally don't use naples yellow because it tends to wash my colors out, but I have to say that it's what I needed for this cat's eye.
Below is my current palette and I may add colors or take away colors now and then, but I encourage you to go out and find your own colors and try as many as you can. Fill bags with color and keep them in storage because you may need that one special color someday.