Conditional formatting formula rules require an active cell. Even if you select a large range like you have in the example above you will still have an active cell. More often than not it is the top left cell of your selection (you can tell because it is selected in a slightly different color than the rest of the selection...)
To translate your formulas exactly. (and assuming it starts in A1 because you haven't given me any cell references to be more specific...)
=A1>30
=A1>60
=A1>90
Even though it just says A1, it will apply itself to all the cells in your selection similar to how dragging a formula down applies to the new cells its in.
Also, similar to dragging a formula, you can lock rows, columns, and both of references you use in conditional formatting... (with a $)
Let's say you are applying the whole range to the values in column A... even if its B, C, D, E, etc... you want to look for a 30 in column A...
You can say =$A1>30
Or to look at the first row ONLY out of a number of columns, you can do =A$1 > 30
To show an example of how you can lock both the row and column... Let's say the 30, 60, and 90 rule are fine for now but you might want to change the values in the future... say have yellow be anything greater than 55 instead of 60... If that's the case you can have some cells on your sheet that have the conditional numbers and reference those cells in the formula.
so on your sheet...
X1 = 30, X2 = 60, X3 = 90 (they can be where ever.. not just X)
Your conditional formulas will then be something like
=A1>$X$1
this means that no matter what cell in the range you're looking at... it will always compare it to exactly X1... X1 will not move with the rest of the range.
=A1>$X$2
=A3>$Z$3
Does that clear things up?