This is my favorite all around everyday "what-should-I-wear" shadow. It's a satin finish which is slightly shimmery and in a natural golden peach. Mac shadows are the best as far as wearability, pigmentation and their unwillingness to crease.
Arena is a color I really like, especially in the summertime. It is a fun satin peach with pink and brown undertones. It is very subtle, but the effect is extremely pretty.
This looks like frosty orange death on me, even though it barely shows up, *even though* I'm a PPP (check my pics if you don't believe me). It looks really pretty in the pan--there are hints of golden shimmer--but it didn't look good on. I tried using this with a darker colour in the crease and no matter which one I used, Arena just looked muddy. Check out Jane Coolest Coral Eyezing if you're considering Arena--it's also lightly pigmented and comes out a similar golden-peach colour, but less frosty and with less orange tones.
MAC's shadows are the best. Arena is a gorgeous peach shade. With a slight amount of shimmer. Simply beautiful.
A good neutral eyeshadow...it has a matte brown/peachy tone. MAC labels it a "satin" correctly; it glides on nicely and feels really soft. A good companion to a natural look.