This can be done with Conditional Formatting and two rules, I've made a simple thing that works with one quirk.
Select the cell or cells you want then on the Home tab click Conditional Formatting, you should see the following:
Click "New Rule" and you should see the following dialog, in which yoou want to select the bottom option "Use a formula to determine which cells to format":
Click the button beside the "Format values where this formula is true" box and select your cell range, so you end up with something like "=K6:K20=1" (minus the quotes) after the second '=' you can put whatever you are matching, text will need to be in quotation marks and you may have to press F4 a couple of times after selecting the cell number ranges to get rid of the $ sign.
Then click the format button to choose the format you are after. You should see something like the standard cell formatting window at this point where you can set it to percentage or currency from the "Number tab"
Click OK to apply it and repeat for the alternate formatting value.
After you've done this you can tweak the settings for it using the "Manage rules" selection on the first image I linked, at which point if you select "This Worksheet" under "Show formatting rules for:" you will see something like this, where you can fine tune the rules, this is what I had.
and what a few sample cells looked like
Keep in mind that percents are measured as 0.2 for 20% and so on in Excel.