The built in picture viewer (Preview.app) can do this:
* Click the pen in a box button next to the search bar. A new toolbar will appear.
* Click the rectangle button between the wand and the oval. Three new buttons will appear. If you mouse over them you can see what they do.
* Draw a rectangle around the area you want to highlight.
* Click the fill color button (it's right next to the border line thickness button)
* Choose "Show Colors..." from the color menu that pops down.
* Select any color and any opacity of that color to fill the rectangle
Here's a of keyboard shortcuts for taking screenshots: http://support.apple.com/kb/ph11229 These shortcuts will put the images on the desktop.
I prefer to use a little tool call SnapNDrag to do screenshots. It's $10 on the app store: https://itunes.apple.com/us/app/snapndrag-pro/id430397512?mt... It's a simple app on top of the operating system's existing functionality. It's just a fancier version of the built in Grab.app.
(Also, if you haven't looked into Alfred or Quicksilver for app launching, I recommend it.)
* Click the pen in a box button next to the search bar. A new toolbar will appear.
* Click the rectangle button between the wand and the oval. Three new buttons will appear. If you mouse over them you can see what they do.
* Draw a rectangle around the area you want to highlight.
* Click the fill color button (it's right next to the border line thickness button)
* Choose "Show Colors..." from the color menu that pops down.
* Select any color and any opacity of that color to fill the rectangle
Here's a of keyboard shortcuts for taking screenshots: http://support.apple.com/kb/ph11229 These shortcuts will put the images on the desktop.
I prefer to use a little tool call SnapNDrag to do screenshots. It's $10 on the app store: https://itunes.apple.com/us/app/snapndrag-pro/id430397512?mt... It's a simple app on top of the operating system's existing functionality. It's just a fancier version of the built in Grab.app.
(Also, if you haven't looked into Alfred or Quicksilver for app launching, I recommend it.)