Not true at all- of course you can use light eye shadow colors
You are lucky because green eyes and auburn hair go so well together. If you hair color stands out, then you will have to adjust your makeup colors to match with your hair color.
Since you said you have auburn hair, I would stick to lips and cheeks with a more peach undertone as this will complement your hair color the best.
NARS Beautiful Liar
NARS Hot Voodoo
Try Laura Mercier Lipliner in Chesnut
or Make Up For Ever Aqua Lip Liner in Chesnut 4C
Laura Mercier Blush in Spiced Cider would be gorgeous on you (the color swatch does not do it justice)
For your eyes, stick with browns with red or orange undertones as these will complement your eye color and hair color the best. Here are some options:
Smashbox Palette Blue Eyes (don't be fooled- it will look great on you too even with green eyes)
Kat Von D True Romance Palette in Ludwig
Smashbox Softbox Palette
Lorac Little Black Palette
Charolette Ronson Palette in Nicole
Dior Holiday Palette
I hope that gives you some ideas and let me know if you need any application tips