The site area, it changes the color blue is almost blue.

Hello komsak,

I suppose that you are referring to the appearance of a flash/time loading when you enter on your website, right? This behavior appears when you have additional customization through custom CSS code and also, I suppose that you are using the Speed Booster plugin. Please notice that the CSS are working in cascade and the first time will take the code from style.css that is set it by default and then the theme will take the custom code that you have changed from Theme panel and practically this flash is generated by this cause. As a workaround, you have to check your style.css and try to add directly in this file your desired custom code. So, if your problem is still there, please try to revert the theme to the default settings, without any customizations and let us know how it goes. Also, you can try to make a new fresh install from scratch with the latest version of the theme and check the results. Also, please make sure every time you cleared caches. Noticed that the only files where you will have to edit are style.css.
If you are not aware of the steps which are needed to take in this regard, please consider hiring a freelancer/developer to help you because we cannot provide custom work at the moment, sorry!

Thanks for your understanding!