If at first you don't like the hue of the pink or yellow sapphire, you may want to ask to see other earrings. Sapphire color varies a lot, and you know how I am about color...I see the slight hue differences, and I split hairs.
For the pink sapphire, some pinks can be a pure pink with a drop of white (my preferred pink), while other pinks have a drop of blue that makes it a bit deeper, but also gives it a blue/purple undertone.
For the yellow sapphire, yellow sapphires can have a drop of red making it look really golden, like an egg yolk, or have a brownish hue. I prefer yellow sapphires to have a drop of white and two drops of yellow for that intense lemon yellow hue.
In gemstones, color is 100% preference; there is no right or wrong, but it's good to have your perfect color in your mind. It eliminates the guessing when looking at only one or two stones at a time.
My point is if you love the earrings, but the stone color somehow doesn't speak to you, ask for other earrings. Sapphire colors vary. When I buy colored gemstones, I go through tons of stones. The best way is to have your perfect pink or yellow sapphire hue in your mind. Use that as the reference, and don't be shy about asking to see a few earrings to pick your shade.