If you want your money to only have a slight brownish tint, then you can add a bit more warm water to the cup. If you don’t have instant coffee on hand, you can instead use a tea bag steeped in a cup of warm water. To create an even more complex color, squeeze out 1-2 drops of green food coloring into the mug and stir quickly. This will give your currency a greenish tint.
You should also note that it is illegal to copy money in color tones in many areas. Instead, you’ll probably need to go with black and white bills. [4] X Research source
This is an especially great way to make fake money for kid’s activities, as it allows you (or them) to put all sorts of images on a bill.
Some educational currency websites will even let you put your own photo or another image in the center of the bill.
Many of these entities offer images of both coin and bill currency.
This is also a good way to get fake money that you know conforms to all legal rules and regulations. However, buying fake money from a prop company can be pricey. Make sure that you understand exactly what you are getting for your money. Most companies will require that you purchase a roll or stack of bills, not just a single bill.
You can also make two-sided copies of currency using most copiers.
