You can change the color of Illustrator symbols / edit a single instance and all the other related instances will also update. Double click an instance. You are now in the isolation mode. Select a path you want to modify and then apply the required swatch etc via the swatches panel etc. Right click and exit the editing mode.
A dialog will pop up (you should know the application loves asking you things). Yes, we need to edit it, so click the OK. Select any part of the image and go to the color panel (window menu) and then modify the setting for that part of the artwork (you can also use the swatches panel)
You can now see a different fills or strokes for the artwork. Now leave the isolation mode and you can do that by right clicking and selecting the exit editing mode or go to the top left and click out of the isolation mode
You will then notice that all the other instances are updated as well as the preset in the panel. If you want to keep both I would suggest that you duplicate the preset before you edit it in the panel
Select an instance and go to the window menu and select the guide and then click bottom line 'edit or apply'. Select an active in the top bar drop down of the panel such as high contrast 1, click the button in the middle of the panel 'randomly change color guide order', click and repeat and you will see the design modify before your eyes, click OK
You will now see the instances have been updated and also the preset in the panel. Another panel will appear and you can then select all kinds of libraries of swatches and even better just click the button just above the H and S sliders on the right of the panel (both direction arrows and three blocks is the best way to describe it) and it will randomize things
You can also modify in a more restrained way by using the sliders in the recolor artwork feature. You can then tweak the hue as well as the saturation and brightness by a degree or two / percentage or two.
If you create it as a dynamic (indicated by a little +), you can use direct selection tool to modify the fill, stroke as well as the opacity and blending as well add additional effects to that part of the design
De-select all the designs. Select one of the paths in the instance using direct selection tool, go to toolbar and set the fill and set the stroke. You can see the selected fill / stroke settings in the tools panel. You will notice now the original presets has not been updated, only the instance you have altered using the direct selection tool.
Select instance, go to the toolbar and sprayer tool and apply some preset instances, go to the stainer in the same group, set the fill (doesn't appear to work with strokes), double click the stainer tool to set options such as intensity etc, click or paint over the instance with the tool. As you apply it you will noticed the selected objects will become more and more pink (or whatever you have in the fill)
Create a square, a basic square with a fill of red and a black stroke. Drag into the panel and use the dynamic option. Drag the preset onto the art board four or five times to fill the art board withg multiple instances or hold down the alt / option key and drag and create multiple instances of your artwork. With the direct selection tool, click on one of the instances. Go to the tools panel and fill color and set it to green. Go to another path and set the fill to blue etc.You can also use the swatches panel, so select the path with the direct selection tool and go to the swatches panel and click a gradient or pattern swatch. Go to path with the tool and then set the stroke and you can change it to red or green etc and change the stroke weight via the properties panel to 60px etc. You can also go to the appearance panel and add additional fill and stroke etc to your square. The underlying source design in the panel is still unchanged.