Learning Week 3 - Shading Colors

I'm officially changing Creature Week to Learning Week, just because I want to just expand my knowledge in all directions, not just organic life. The only rule is I cannot draw things I'm comfortable with _{so basically I can draw anything}

Sorry for the late posting by the way, I got sidetracked and forgot to post it
This week is practicing shading! Each ball I tried something different:
Value: I simply drug the value up and down to get my colors, no hue changing
Hue Down: I drug both the hue and the value down this time for the shading, and up for the lighting (so cooler shading and warmer lighting)
Hue Up: I drug hue/value up for the shading and down for the lighting to see the opposite effect
Analogous Green/Red/Blue: I used the color's analogous (opposite) color for the shading, and went ahead and kept yellow for the lighting

I was going to keep on using green in different ways, but once I got to the analogous step I realized not only have I been told my entire life that's the color to use, but it looked so much better than the other. So to test it I tried shading two different colors with their analogous color. The first blue I chose ended up with yellow as it's opposite, and when I tried to shade it the color just ended up looking muddy and gross. So I picked a new blue with red, which looks much prettier.
Conclusion: Shade with blue/purple, but if you're using blue use red and purple probably uses green?

I found out while doing this my painting skills are kinda eh too, so I'm thinking this week I might try painting fur or something