change changed status's color to blue

closes #256 (closed)

• Change the changed status's color to blue from red which is more of the color code for error
• Set up in view/util/color.py the dict COLOR with meaningful color name.
• In database dialogs, change also the background of changed widgets to light blue for case that it is changed to empty. This won't affect valueColorEdit and combo box. (Changing border won't be consider because it change styleSheet which will affect the appearance of button on widget like combo box or spin box)