Fable III

This achievement can be done after you finish the quests for Sabine in Dweller Camp. When you complete all three of Sabine's tasks return to the Dweller Camp....cut scene... Then on the ROAD TO RULE make sure you get both Dye Packs
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Dye Pack 1 is at the second gate on the ROAD TO RULE, if you did not already get it make sure to go back and grab it only 2 Guild seals.
The second Dye pack you need is just though the fourth gate only 5 guild seals.

The long hair can be bought in Brightwall Village at the Stylist just over the bridge for 250 gold. Go to your Dressing Room and pick a suit. I went with the prince, get the long hair then got to you Dyes between the two candles.

Start from the top most dye and work your way down the rack. DON'T WORRY ALL DYES CAN BE RESET. One dye for each texture ex: upper body main and another dye for upper body trim. There are 6 separate pieces to dye and you have 8 dyes. That's all it takes.

P.S.
I don't think your hair has to be dyed but you do have two extra dyes.

When you unlock most/all of the road, and have bought the dyes, all of them preferably. Then go to your outfits (I used the prince oufit because I thought that would be easier) and then go to your dye wall and start from the top and work your way down (ex Red - Hair, Blue - Hair Trim and so on) then after you have each part of your outfit a different colour you've completed that part.
For the long hair I used the hairstylist in Brightwall, just walk in and go to the long hair style (costs 238 gp) and just go to your dressing room and put it on and it should unlock.

Edit: Main and trims have to be different colours.

In the road to rule you get dye packs which then you get an outfit and just die each part a different colour. After then you have to aquire the long hair by buying or stealing it from shops.

I had a problem with this one as well. What worked for me was wearing pajamas with gloves which gave me the option to dye hands. Popped right away,

colour all your clothes with much differents colors , see this youtube video ....

(( you see the achievement unlocked at the end of this youtube video at 1 ' 12 " ))