Yorkies come in different shades and colours. Really good breeders work hard to get the colours they're known for (and other ideal qualities). It takes years and years to achieve a champion bloodline pedigree. However, even when breeding the best with the best, the litter can still sometimes differ from how the parents look. So, when these really good breeders breed from only the best, the ones they sell as pets will generally
not have the perfect qualities. It's just that you have a higher chance of getting a beautiful Yorkie from a good breeder.
Then there are the other breeders who aren't breeding for the better of the breed, in which case there are definite no guarantees.
In any case, he's only 8 months. Their colours change during the first 2 to 3 years of their lives! So in short, no, he won't stay this way. Having said that, I wouldn't be too concerned or insistent about achieving certain "rich gold & dark steel blue" colours - it's nature's doing and not really up to you

. And...I don't find his colouring "dull" at all.