Are two different color apples considered to be different minim for the purposes of Mishloach Manos? They do taste different from each other.
It is not so clear if one needs 2 separate items. However, the gemara in megila 7a seems to imply that two different items should be used. This is how the Aruch Hashulchan (695:14) seems to hold. So if you send a dark piece of meat and a white piece of meat those are considered two separate manos since they taste different. Rav Eliyashiv (Ashrei Ha’Ish pg 311:5) holds that two different drinks counts as two manos. So it seems according to this two different apples would count as two separate manos, especially if they taste different. Rav Eliyashiv also held that two big pieces of the same thing may be considered two separate manos. However, he held that one should be machmir and use different items,or at least two separate parts of a chicken.
Rav Shmuel Kamenetsky in Kovetz Halachos 17:2 holds that one should not use two of the same thing, based off the Aruch Hashulchan 695:14. See also Eshel Avraham (Butschach) 695.
Text of Ashrei HaIsh:
Rav Shmuel Kamentesky in Kovetz Halachos 17:4 brings this exact question whether a red and green apple which have different tastes are considered two manos. He holds that it is considered one min and one would need an additional item. He also holds that red wine and white wine are also considered one min. However, see my other answer.