Bronze 5 Mils are from the years 1942 and 1944. All other 5 Mils are copper-nickel. How can you tell for sure it is bronze? Maybe its just a nasty looking orange corrosion.
Bronze, in this case, is not really yellow, but red-brown. Pictures would help, if you can make and upload some.
Palestine 5 Mils 1927 KM 3 Copper-nickel 20 mm diameter. Value in Fine $0.75 Your coin would not make Fine. With a value that low the chances of it being a fake are very small.