I’m almost 90% sure this is not possible but out of desperation, I have to ask. Is it possible to change color or some other property of defined styles dynamically?
I have a design system, for example, 10 colors that I am using all-around perspective. If I want to change one of my colors I have to open each defined style class and to change it?
Yes, style classes can’t be changed dynamically because they’re loaded into the Perspective session once, during initialization, as compiled CSS classes.
If you just need to make a one-time change, it might be faster to manually change the resources on disk - if you go to ${ignition installation directory}/data/projects/${yourProject}/com.inductiveautomation.perspective/style-classes/${path/To/Your/Style}/style.json, you can open the style as a plain-text JSON file and make edits. You could use some tool (Notepad++, sed, etc) to find/replace ${old color} with ${new color} in all the style class files at once.
Yes, but still I need to open each of the file almost the same as to open it from designer.
I didn’t express myself well, no dynamically, as dynamically during season. More something like possibility to define color (or some other property) in style class as other style class :). For example if I have pallet from 10 colors, I am going to make 10 style classes for each color and then I am going in style class for example for samo status to use one of the 10 style classes defined with my color system.
I am working for the first time with Ignition. For more than 13 years I am HMI developer and I never spend so much time with styling components. It’s really time consuming. 
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Style class ‘inheritance’ or ‘composibility’ is something we’re planning to revisit or improve in the future. Once a large push to revamp Perspective’s built-in themes (and the theme-ability of components) is available within the next few releases, it’ll also be possible to write your own master theme CSS file that controls the appearance of all components in one file - as long as you’re comfortable writing your own CSS.
I am looking forward to it. Thanks!