How to use the node editor to paint an object that uses more than one color, Type a character?
Moved from “Tutorials, Tips, and Tricks” to “Materials and Textures”
Tipical method is to paint an image texture and use that texture in the material, using the ‘image texture’ node.
But there are plenty more ways to do it… So if you can be more detailed in your question… 
Good afternoon!
What I want to know about the features of the node editor is redistricting more than one color?
It has this link that follows in the post of the image of the character where it has two colors. It has this color ramps feature being simpler. There is something more advanced for more elaborate use for characters.
As I said above, there are lots of different options to choose from… And again, you need to be more specific in the problem you’re having (which right now seems that you want the ‘complete manual’ for texturing).
Colors can be originated from different sources. How do you choose these sources is up to you, and each has pros and cons that you need to ponder. And they depend also on different factors like the type of coloring, the type of object, the type of project, deadlines, your skills, your rendering system, and much more.
The basic stuff is: A color is composed of three components. Three values (typically from 0 to 1) for the Red, Green and Blue colors. Mixing these in different quantities will give you all the colors you need.
The node editor has different options to input variables. Image Textures are one of the most common, vertices colors can also be used in some situations, procedurals are also quite common. Mixing and masking is also a typical workflow with any of them.
For something like the turtle you posted, It’s a painting job! You need to create an image texture, apply it to your model and paint on it. Read the manual, if you haven’t done it yet.
Your second example is something that we could call ‘a procedural based texturing’, where one coordinate component drives a color ramp.
Again, knowing what each node does is important, and reading the manual also!
A search in google for ‘blender painting’ or ‘blender texturing’ will show you a great amount of videos and pages with probably much more than you can digest in one day, but give it a try.
I’ll read and try. Thank you!