Looks like the Royals' home gold number alternate didn't get fixed for '18.
The in-game uniform still has blue piping on the front of the jersey.
I'll preface this and say that I don't know anything about coding, but the jersey is literally just a duplicate of the base home jersey, with the same blue Royals script on the front, just with an added gold outline, and then the numbers are turned to a gold color with a blue outline. The 'design' of the jersey is no different. Just different colors.
I know that colors can be a touchy subject, but I also think the color on these jerseys needs to be more champagne, and less gold/bronze. I looked at it in different lighting a few times in MLB 18, but I can never get it to look like the brighter champagne color that the real pictures show it as. FWIW, I also actually own one of these jerseys and the pictures of Salvy and Hos here are very true to how the jersey looks in person.
IN-GAME
REAL LIFE