Light Bluish Grey is the BrickLink term for what LEGO (and Mecabricks) call Medium Stone Gray. They're the same color. It's the light grey color in the main color palette. The Mecabricks color chart pdf is an excellent resource. Unfortunately, access has been spotty lately due to a server issue and some browsers having an issue with too many redirects. I'll provide a link to an online color translation list from Peeron as well. Most of the newer color names match up between BrickLink and LEGO/Mecabricks, but many just don't. For instance, what you think of as Tan is officially called Brick Yellow by LEGO. Whatever. It's their product, so they can use weird names I guess. Scrubs has chosen to use the LEGO convention for color names, so there is an amount of translation between stud.io and Mecabricks.

Here's the Mecabricks color chart (link may or may not work):
[url]http://www.mecabricks.com/docs/colour_chart.pdf[/url]

Here's the online translator:
[url]http://www.peeron.com/cgi-bin/invcgis/inv/colors?PagerSortDir=f&PagerSortCol=BLName&PagerSortRev=0[/url]

Now as far as the actual RGB colors being different, every digital platform (LDD, stud.io, Mecabricks, LDraw, etc) is different on most colors. Scrubs' pdf (which seems to be inaccessible at the moment) has the RGB values for each color on each platform listed out. It is up to the designer of the modeling software to decide on the color palette that will best represent ABS plastic colors on a computer monitor. So your models from stud.io will probably not match exactly with models from Mecabricks, but for most colors they will be pretty close. Bricklink's RGB version of Light Bluish Gray is way different than everyone else's. To say that the Mecabricks colors here do not represent the actual plastic colors I think is a little inaccurate.

One last thing that may be helpful (but may introduce new issues) is that you can import your stud.io models into Mecabricks. This will automatically translate the colors between the software systems for you. Unfortunately, you may run into issues with parts in stud.io not being in Mecabricks or the odd import error. However, it may or may not be worth giving a shot.

Good luck!