Killer Instinct

Shadow Jago had a limited edition figure that came with a exclusive number ten costume color for his default costume. Using this code will unlock the achievement immediately upon loading the game.
They also made the character officially playable for those that didn't buy a Day One Xbox Live subscription card by buying a bundle that included KI Gold, this could be used to buy a costume color in the in-game store.

The above is not really a guide but a explanation for why Shadow Jago's "Stylish" achievement has a higher percentage compared to previous characters.
If you received the character from the Day One card or bought the bundle but don't wish to use your KI Gold on a costume color simply play three matches or so and you'll unlock your first costume color when you're experience gained with the character reaches three.
Performing special moves, doing throws, blocks, combos and ultras will get you character experience and it's possible to hit level three experience mid-match.

Shadow Jago earns a new color after lvl 3. You'll get enough XP for this while passively playing 200 matches. Idling is good enough for this achievement, but you will earn it faster while going for 10 survival wins.

For those that didn't have the version of the game of the other guide:
Colors for each character unlock at Level 3, so go into Survival or any of the fight modes and win 2 or 3 matches, preferably doing some of the fight challenges associated with each character