Eva Theme for VS is converted from Eva Theme for VSCode using theme-converter-for-vs. Since it is hardly to directly edit the target syntax color when converting the theme. So, actually, the UI and Syntax color settings of Eva Theme for VS are separated. The Syntax color settings of Eva Theme for VS is used by fonts-and-colors.vssettings file, and will be as consistent as possible with the characters' color in VSCode.
The setting position of fonts-and-colors is in Visual Studio 'Tools → Options → Environment → fonts and colors'. Some setting options in "font and color", I can’t understand what they are by just looking at the name. If you understand the meaning of an option and find that its color in Eva Theme for VS is different from the color in Eva Theme for VSCode, you are welcome to submit an issue, attach screenshots and code snippets.