Many people comment that they like my color palette. You can see what tubes I get on my workshop page. It is actually not that easy to translate the actual world into paint pigments, but we painters always try.  Every painter has their favorite colors they work from especially greens.Some artists prefer to never use green paint . They mix all their greens from blue, red and yellow. Other artists use only one green such as viridian green or sap green to mix in their other colors. I know one who uses pure viridian green on skin tones. You would never know it . 
So the more we play with our palette the more colors and nuances we get. 

 We had our"Plein Air"Painting workshop on October 15th, 2011 at the Eldorado Natuire Center. First, I showed a demonstration on  composing a painting from start to finish. The students learned a lot about color mixing, design and brush techniques. 

After lunch, they did their paintings. This was the first time for some of them and already they are learning not to use paint straight from the tube! Look at all those greens they are now using!

There are many "plein air" painting (outdoor painting) workshop classes to choose from these days, you can study under famous teachers or someone whose work you admire.  
  I have been to a few myself, including workshops from Jacobus Baas, Erin Dertner, Corrine Hartley and Greg La Rock. Although they each have their unique style, they all teach the same basic points which are composition,  focal points, creating a pleasing flow in the painting, values 
and the use of color intensity. 
  Don't expect to go to a workshop and come out painting like the teacher.  But, you should challenge yourself to try new and different methods. Try their color mixes, brush or palette knife techniques, canvas etc. You may or may not add it to your repitiore, but you will  learn or re-learn the the same basic points seeing them in just a different medium or technique. 
  Also choose a teacher who talks a lot while they demonstrate. It is lovely to watch some one paint , but if you do not understand what they are doing it will not be helpful.