To search a list against another list follow these steps to find different values
1. Select the range or list which contains values to be compared
2. Click Format --> Conditional Format
3. Select Formula Is from drop down
4. Enter this formula COUNTIF($Range,$Cell), where $Range is the list which will be compared against and $Cell is the cell where list in #1 starts. i.e. $Range = $A1:$B2 and $Cell = C2
5. Click Format Style and select formatting such as pattern or font color.
6. Click Ok
7. Result will show cells with new formatting selected in last step.