Today will be focusing on 3 colors as well as playing more with water and pigment ratios and combinations. The 3 colors are Cobalt BLue (C), Rose Madder Genuine (RMG) and Auroline Yellow (AY). These 3 pigments are both transparent and non staining. Because of the latter play with lifting colors off your paper! You can go back to basically white if you dont dig too deep into the paper with your brush.
So in this see how I had more water on the left? I used my brush to lift off some of that water then out some pigment on the tip of the brush to put some in so the color would be darker.
Rose Madder Genuine- see where the color was put onto the wet paper? I let the gravity of the water pull the pigment.Yellow is a very difficult color to use. Too pigment and it goes dead.Play varying pigment amounts and see what
it looks like to you! 
Tray making a color wheel. First draw 3 circles, ovals whatever equal distance on a piece of paper. Then in one pu t CB, another AY and in the other RMG. THose are your 3 primary colors. Next between each of these bubbles put another circle here paint secondary colors. Try mixing these both on the paper and in the bubble. In the purple bubble you can see where I partially mixed RMG and CB on the palette. Once you have your seconday colors put 2 circles in between each of the circles. Move from blue to blue blue green to blue green to green to yellow green to yellow yellow green to yellow.
Now do this for all the bubbles between the other primary and secondary colors. A glowing orange will be hard to achieve because RMG has a bluish cast as does AY. If you have the resources I highly recommend the pigment Opera for it is a warm pink that with a yellow like Winsor Yellow makes a truly singing Orange! But for now RMG and AY will work. (The sun in the feature image was created with Opera and Winsor Yellow).
This can be a very meditative exercise. Pay attention to water and pigment amounts. Try lifting pigment out putting more pasty pigment in. What do you observe? I hope you will consider sharing your observations!
I have painted many a painting with just these three colors. Play with combinations of all three to see what quality grays you can achieve ( see middle of color wheel.)