Seems like Rails do caching, which I don't want it to - ruby-on-rails

Question

There is #avalibable_colors=['#5A009D', '#004DFF', '#F4F400', '#FF8000'] variable (it is not instance of model), which represent avaliable options - colors, which hadn't been taken yet, through method:
def choose_color
#check=Check.find(params[:check_id])
#colorschemes=#check.colorschemes
current_colors=[]
#check.colorschemes.each do |c|
current_colors.push(c.color)
end
#avalibable_colors=['#5A009D', '#004DFF', '#F4F400', '#FF8000']
current_colors.each do |c|
if #avalibable_colors.index(c)
#avalibable_colors[#avalibable_colors.index(c)]=nil
end
end
#avalibable_colors.compact!
respond_to do |format|
format.js
end
end
After that #avalibable_colors contents only untaken color options.
And generally it works. If I choose 1 color option, it displays rest 4, if 2 - rest 3, if I choose one, and then delete it - it is in avaliable colors.
And that works until whole four. And If I add all four, and then delete one by one, no colors are avaliable until I refresh page.
Server logs:
Started GET "/choose_color?check_id=46" for 127.0.0.1 at 2013-06-13 19:00:31 +0400
Processing by ColorschemesController#choose_color as JS
Parameters: {"check_id"=>"46"}
User Load (1.0ms) SELECT "users".* FROM "users" WHERE "users"."auth_token" = 'oPXJtztDkYdYmVsQ3wxxfQ' LIMIT 1
Check Load (1.0ms) SELECT "checks".* FROM "checks" WHERE "checks"."id" = 46 LIMIT 1
CACHE (0.0ms) SELECT "checks".* FROM "checks" WHERE "checks"."id" = 46 LIMIT 1
Check Load (1.0ms) SELECT "checks".* FROM "checks" WHERE "checks"."id" = $1 LIMIT 1 [["id", "46"]]
Colorscheme Load (0.0ms) SELECT "colorschemes".* FROM "colorschemes" WHERE "colorschemes"."check_id" = 46
Rendered colorschemes/_choose_color.html.erb (0.0ms)
Rendered colorschemes/choose_color.js.erb (5.0ms)
Completed 200 OK in 33ms (Views: 22.0ms | ActiveRecord: 3.0ms)