When you load a RAW image into ACR it applies the Adobe default profile, which is usually pretty awful.
You can make a custom profile that has nothing added to it if you want, and then when you import all your images just apply that new profile globally.
Even better you can buy something like the Colorchecker Passport, make yourself a few profiles (i.e. Sunlight, Shade, Overcast, etc.) and get technically perfect color/contrast in a few clicks - afterwards adjust to taste if desired. This is my favorite approach (and the biggest time saver I have found when processing thousands of images) but everyone is different.