I don't know much about sun faded cards because that is not how I do it. Once you see a card faded in the sun though you will be able to easily spot them in the future. All cards exposed to daily light will fade.
No matter how you "fade" the cards the colors that are removed or lightened vary greatly from year to year and brand. Some lose the yellow first, some lose the red first and some it is easiest to see in the black. The amount of color and how fast they are removed also varies greatly by year/brand.
Here is a pic of a "faded" 58 Hank Aaron I done and then got graded by SGC. I removed all the yellow except in the logo. Sorry for the bad cell phone picture. I hoped after I done this and posted about it before was that it would save people from paying a premium for an altered card. Unless you are looking for the only known blue front 58 Aaron with a nice yellow logo because it will command a huge premium.
If you search this site for Blue 1958 Aaron you should find some good info.