Firstly, there are a few armor types that can not be dyed, like Unique, Draconic, and Abyss armor. The NPC named Jooma, that sells the regular dyes in Sanctum is located in the cloth shop. Looking at the map, the shop is in the bottom right corner. Jooma also gives a quest to get 5 dyes of your color choice at 19.
As for the Collectors edition Dye, the color will be Rich Purple, and it's been mentioned that you can dye armor up to 10 times. each character created on your account will get this dye.
[Dye: Rich Purple]
Regular Dyes:
[Dye Remover]
Thanks to BrizaBlackheart for a comprehensive explanation of Petals.
Besides the ones you can buy, or that drop off of mobs, there are also Dyes you can harvest called Petals. Just like regular dyes, you can apply them by right clicking them and selecting the armor you wish to dye. Each faction has 7 Petals that can only be harvested in those factions zones. So if you want the Petals that are from Asmodae, you will have to jump a Rift to get them.
*The reason why some of the Elyos petals say Asmodian Only, is due to an Asmodian quest that gives those petals, aionarmory used that for the item list instead of the petal dropped ones. Fear not, if you get that petal you'll be able to apply it as Elyos just fine.
Starting with the Elyos, the first Petal you can harvest is the Wiki, which requires a harvest skill of 110.
Plant:
[Wiki] Petal: 
[Wiki Petal]
Second Petal for Elyos is the Umbilia, which requires a harvest skill of 165.
Plant:
[Umblia] Petal: [Umblia Petal]
The third Petal, is the Meon, which requires a harvest skill of 220.
Plant:
[Meon] Petal: [Meon Petal]
The fourth Petal, is the Ormea, which requires a harvest skill of 260.
Plant:
[Ormea] Petal: [Ormea Petal]
The fifth Petal, is the Tange, which requires a harvest skill of 325.
Plant:
[Tange] Petal: [Tange Petal]
The sixth Petal is the Ervio, which requires a harvest skill of 355.
Plant:
[Ervio] Petal: [Ervio Petal]
The final Elyos petal is the Lunime, which requires a harvest skill of 385.
Plant: [Lunime] Petal: [Lunime Petal]
And now the Asmodian side of Petals, the first being the Vinna, which requires a harvest skill of 135.
Plant: [Vinna] Petal: [Vinna Petal]
Second Petal is the Kirka, which requires a harvest skill of 180.
Plant: [Kirka] Petal: [Kirka Petal]
The third Petal is the Brommel, which requires a harvest skill of 240.
Plant:
[Brommel] Petal: [Brommel Petal]
The fourth Petal is the Pressa, which requires a harvest skill of 275.
Plant:
[Pressa] Petal: [Pressa Petal]
The fifth Petal is the Merone, which requires a harvest skill of 325.
Plant:
[Merone] Petal: [Merone Petal]
The sixth Petal is the Kukar, which requires a harvest skill of 355.
Plant: [Kukar] Petal: [Kukar Petal]
The final Asmodian Petal is the Leopis, which requires a harvest skill of 390.
Plant: [Leopis] Petal: [Leopis Petal]
Rare Dyes:
Rare dyes are dropped off of elite mobs. and some have been used for rewards and events
[Dye: Mustard]
As for the Collectors edition Dye, the color will be Rich Purple, and it's been mentioned that you can dye armor up to 10 times. each character created on your account will get this dye.
[Dye: Rich Purple] 
Regular Dyes:
 [Dye: Blue] |  [Dye: Brown] | [Dye: Purple] |  [Dye: Turquoise] |
 |  |  |  |
[Dye Remover]Thanks to BrizaBlackheart for a comprehensive explanation of Petals.
Besides the ones you can buy, or that drop off of mobs, there are also Dyes you can harvest called Petals. Just like regular dyes, you can apply them by right clicking them and selecting the armor you wish to dye. Each faction has 7 Petals that can only be harvested in those factions zones. So if you want the Petals that are from Asmodae, you will have to jump a Rift to get them.
*The reason why some of the Elyos petals say Asmodian Only, is due to an Asmodian quest that gives those petals, aionarmory used that for the item list instead of the petal dropped ones. Fear not, if you get that petal you'll be able to apply it as Elyos just fine.
Starting with the Elyos, the first Petal you can harvest is the Wiki, which requires a harvest skill of 110.
Plant:
[Wiki] Petal: [Wiki Petal]Attachment:
Second Petal for Elyos is the Umbilia, which requires a harvest skill of 165.
Plant:
[Umblia] Petal: [Umblia Petal]Attachment:
The third Petal, is the Meon, which requires a harvest skill of 220.
Plant:
[Meon] Petal: [Meon Petal]Attachment:
The fourth Petal, is the Ormea, which requires a harvest skill of 260.
Plant:
[Ormea] Petal: [Ormea Petal]Attachment:
The fifth Petal, is the Tange, which requires a harvest skill of 325.
Plant:
[Tange] Petal: [Tange Petal]Attachment:
The sixth Petal is the Ervio, which requires a harvest skill of 355.
Plant:
[Ervio] Petal: [Ervio Petal]Attachment:
The final Elyos petal is the Lunime, which requires a harvest skill of 385.
Plant:
[Lunime] Petal: [Lunime Petal]Attachment:
And now the Asmodian side of Petals, the first being the Vinna, which requires a harvest skill of 135.
Plant:
[Vinna] Petal: [Vinna Petal]Attachment:
Second Petal is the Kirka, which requires a harvest skill of 180.
Plant:
[Kirka] Petal: [Kirka Petal]Attachment:
The third Petal is the Brommel, which requires a harvest skill of 240.
Plant:
[Brommel] Petal: [Brommel Petal]Attachment:
The fourth Petal is the Pressa, which requires a harvest skill of 275.
Plant:
[Pressa] Petal: [Pressa Petal]Attachment:
The fifth Petal is the Merone, which requires a harvest skill of 325.
Plant:
[Merone] Petal: [Merone Petal]Attachment:
The sixth Petal is the Kukar, which requires a harvest skill of 355.
Plant:
[Kukar] Petal: [Kukar Petal]Attachment:
The final Asmodian Petal is the Leopis, which requires a harvest skill of 390.
Plant:
[Leopis] Petal: [Leopis Petal]Attachment:
Rare Dyes:
Rare dyes are dropped off of elite mobs. and some have been used for rewards and events
[Dye: Mustard]Attachment:
[Dye: Green Tea]Used as part of the St pats day event, if you logged in during that time, you got a survey wuth 5 free dyes
[Dye: True White] Offered as a choice when you pre-order before 26th March 2010 Aion Official Magazine
[Dye: True Black]
[Dye: True Black]
[Dye: True Red] True red and Hot pink were offered during valentines day events as a prize
[Dye: Hot Pink] 
[Dye: Hot Orange]
Another way to get the Rare Dyes is via Legion Rewards, which can be attained by capturing Fortresses, and later be purchased with Reward points. Similar to Abyss rewards. Here are the dyes that are only attainable via Legion Rewards.
Legion Reward Dyes:
[[Legion Reward] Dye: Hot Rubus]Event Dyes are another kind of way to get the rare dyes, and one special color. I'm unsure how these are acquired, other then the obvious, 'during an event, duh!'. Here are the dyes that are only attainable via Event Dyes.
Event Dyes:
![[Event] Dye: Romantic Purple](https://lh3.googleusercontent.com/blogger_img_proxy/AEn0k_uPVJGbi7VolWOywJV-7oiIAOtQQ_duqA4piwSKebt_EM6DYKzXor1tleItcaMREnCPQZF7TmTLeAn96qyYPfOciCJ4v9cu1Ch3wIypq8I=s0-d)
[[Event] Dye: Romantic Purple]
