Color Creator is an iOS app for creating Colours from RGB values.
Just move the red, green and blue sliders until you get the colour you want. You can fine-tune the values using the 3 steppers.
The values are displayed in decimal and hex. You can also copy these values to the clip-board.
The colours can be saved for later. Also, the app uses the Cloud so your colours will be available on all of your iOS devices.