There are two standards, you can pick either it doesn't matter. You use the same pattern of colors on both sides. (The colors different between the standards, but the difference is cosmetic, not electrical.)
That means pin 1 is the same on both sides, the devices using this cable have to be different, like a network card on one side and a switch on the other. Internally the two devices have opposite meaning of what wire is receive and transmit.
Or you can use one standard on one end, and the other standard on the other. This makes a crossover cable, where the receive and transmit pairs are swapped.
This is good when connecting two devices that both have the same belief about which pin is receive and transmit.
These days people got tired of dealing with that and most devices auto negotiate which pin is which, and the type of cable doesn't matter.
That means pin 1 is the same on both sides, the devices using this cable have to be different, like a network card on one side and a switch on the other. Internally the two devices have opposite meaning of what wire is receive and transmit.
Or you can use one standard on one end, and the other standard on the other. This makes a crossover cable, where the receive and transmit pairs are swapped.
This is good when connecting two devices that both have the same belief about which pin is receive and transmit.
These days people got tired of dealing with that and most devices auto negotiate which pin is which, and the type of cable doesn't matter.