So I have made a little discovery.
If you install the Intel drivers from Intel website, and discover that you have problems with the Surface Pro switching between headphones and speakers, I have found a workaround fix.
1- Install back the system firmware update again to return back to the original drivers.
2- Get the Intel latest drivers .zip file, which you extract
3- delete the *.cat file inside (this is the driver signature)
4- Delete the folder "DisplayAudio" (this is the driver that causes problem)
5- If you are under Windows 10, edit the *.inf file under "Graphics" folder (igdlh64.inf) with Notepad, scroll down to "Windows 8.1 Install" section (you'll notice it in a box. Should be at Line 165)., and change "[IntelGfx.NTamd64.6.3]" to "[IntelGfx.NTamd64.6.4]", save and close. Again, this applies to Windows 10 users only. This is needed to make the drivers install under Windows 10, else it won't.
6- Open Device Manager, go to "Display adapter" > "Intel(R) HD Graphics". Right-click on it, and select "Update Driver Software"
7- On the panel that just showed up, select "Browse...", then on "Let me pick...", then on "Have Disk" button, then on "Browse", pick the location of the Intel drivers that we just worked on, and go under the "Graphics" folder, and select the *.inf file.
8- Click on "Next" and it will install. Restart your system, and you should be ready to go.
9- Use Surface Tweak Tool to to apply the lack of color fix, start the Intel Control Panel, go under "Power section, then click on "Power" at the top left corner, a menu will show, select "Battery", and click on "Disable" for the option "Display Power Saving Technology". Make sure that "Graphic Power Plan" remains at "Maximum Battery life", if not, set it back to (this is important to keep the battery life of the Surface the same). And voila.
It must be noted: Audio through DisplayPort connection might no longer work. I don't have the equipment to test, but your headphone/speaker switching problem when you plug/unplug headphones/speakers on the audio jack, should be solved.