Do you have a RFduino or Simblee?
You mention RFduino, but you are asking in the Simblee section.
What kind of multicolor LED? The digital neopixel type like WS2812 are complicated. I won't explain this.
Or, the simple 3 separate LEDs in one package type like what comes with the RFD22122 RGB/Button Shield.
For RFduino there is...
There is an example sketch for this under File->Examples->RFduinoBLE->ColorWheel
And there was a iPhone called the ColorWheel for this.
For the Simblee the same iPhone APP should work. But, I forget if there was an issue with it.
There is an example sketch for this under File->Examples->SimbleBLE->ColorWheel
However, for the Simblee the better approach is to use Simblee For Mobile instead, then you can use iPhone or Android.
There is an example sketch for this under File->Examples->SimbleeForMobile->ColorWheel