You need to understand that RGB fans do NOT do their own colour things. Every RGB device (including fans that have RGB units in them) must be plugged into a combination power supply and controller. In fact, the Controller part that creates the changing light displays does that by supplying power to just the right LED units in the lighting device.
It is very likely (but NOT guaranteed) that your ASUS mobo will have a RGB header on it that can do this job for you. It does that when you install and use their ASUS Aura Sync software utility that does all the creating of lighting effects and manages the output of the mobo RGB header.
You will need to understand lighting devices, though, and match what you buy to what you have. The simplest fans with lights in them and first on the market were called LED Fans. In them, there is ONE colour of LED connected in parallel with the fan motor, so it is always lit when the fan is running, but it does not change. This is NOT an RGB fan!
There are two types of RGB lighting devices dominating the market now, and they are different and incompatible - you cannot mix them. That is why matching is important. The plain RGB devices have along their strips three colours of LED's - Red, Green and Blue. All the LED's of one colour are connected together. These devices use a 4-pin connection that provides a common +12 VDC supply line and three separate Ground lines, one for each colour. Control of the Ground lines and mixing of colours can produce a large range of colours, but at any one moment the entire length of the strip will show the same colour.
The more complex design is called Addressable RGB or ADDR RGB or just ARGB. Along these strips the three LED colours are all grouped into Nodes. Each Node has one LED of each of the three colours, plus a controller chip. This system uses a THREE-pin connection supplying +5 VDC and Ground for power, and a Control Line which carrries a series of instruction packets each containing a Node address. Along the strip, all the Controller chips listen to the Control Line and each responds only to an instruction packet addressed to it, making its three LED colours do what they are told.Thus this device can create much more complex displays such as a rainbow effect that chases iteslf along the strip.
You can see that the power supply voltages and control mechanisms of these two designs are very different. So you MUST match the lighting device type (and that includes any RGB Fan) that you buy to the Controller type you have or buy. If your mobo has a plain RGB header with 4 pins, then you must plug into that only plain RGB type devices. If your mobo has an ADDR RGB header with 3 pins, you must use only ADDR RGB devices with that. Some mobos have one or more of each of those, so you can use whichever you prefer. Some mobo have none, so then you need to buy a separate controller of eoither 4-pin plain RGB of 3-pin ADDR RGB type.
Mobo makers that include RGB headers of either type on the board supply thjeir own custom software tools for using these headers. ASUS supplies Aura Sync, Gigabyte supplies RGB Fusion, MSI supplies Mystic Light, etc. Each of these can controle EITHER type of header on their mobo. So the name of the RGB control system does NOT tell you which type of lighting device you need. You must match your lighting device type to the physical pin configuration of the header you have - 3-pin ADDR RGB, or 4-pin plain RGB.
An "RGB Fan" actually has two electrical cables to it. One is strictly for the fan motor and is exactly the same as any non-RGB fan connection. It may be either the older 3-pin Voltage Control Mode fan, or the newer 4-pin PWM Mode fan. Separately there is the cable for the RGB lighting device contained in the fan chassis, and this will have either a 3-hole connector for an ADDR RGB system, or a 4-hole connector for a plain RGB system. (The sizes and spacing of pins for motor connectors and RGB lighting device connectors are quite different.)
Most RGB headers of either type can supply up to 3A of current to all of the devices plugged into them. If you have more that one device of the same type to connect to a single header, you can buy RGB Splitter cables that convert one mobo output header into three outputs for devices. There are even some RGB Hubs that can provide more outputs, but you must adhere to the limit on total current the header can supply. If you use a Sp[litter, each device you connect to it will do the same as the other devices because they all share the same power and control signals from a single header.