The DX4 and the ST10+ use different technology. The Chroma is built to use either, but you have to replace the Reciever in the Chroma with the one for the ST10/ST10+. The Chroma already has connections for either reciever.
The Chroma part number is : BLH8607
These are listed as out of stock.
The actual reciever board is the same for any Yuneec drone that uses the ST10 series controller. The color and length of the wire is different. And they use several variations in the antenna wires, which you can probably swap for yours.