What do you mean by "colorscheme", and more particularly, what do you mean by "the hex values of the default colorscheme"?
If you're asking about particular colors that you see, where do you see the colors you're interested in?
If they are for buffer text, put your cursor on some text with a particular color and do
C-u C-x =. Buffer
*Help* will tell you what face is used for that text and provide a link to its description, which shows any colors used (foreground, background, etc.).
If they are for the default frame background and foreground, use
M-x describe-face default; the attributes of face
default are used as frame defaults.
You can also use
M-x list-colors-display, to see all of the available defined (named) colors, along with their hex RGB values. It's likely that the default colors are among those shown, and you can probably find colors that match what you see.