On this episode of The Young and the Restless, Sofia attends the twins' christening. She is wearing a bright yellow printed dress that appears to be the one below.
A similar dress for less than half the price would be this one.
As for Sofia's chunky yellow necklace, if it looks familiar it is because she already wore it in the July 20, 2010 episode.
To get one similar, see this necklace.