Why did Bundle Update alter CSS?

I ran bundle update and now my background color $body-bg: #2c3e50; is now white and a few little css things have been altered.

Do you know why this is and what I can do to fix it?

I'm open to redoing bundle install if there is a way to do that - not ideal though.

source 'https://rubygems.org'

gem 'rails',                '4.2.0.rc3'
gem 'sass-rails',           '5.0.0.beta1'
gem 'uglifier',             '2.5.3'
gem 'coffee-rails',         '4.1.0'
gem 'jquery-rails',         '4.0.0.beta2'
gem 'turbolinks',           '2.3.0'
gem 'jbuilder',             '2.2.3'
gem 'bcrypt',               '3.1.7'
gem 'will_paginate',        '3.0.7'
gem 'bootstrap-will_paginate', '0.0.10'
gem "letter_opener", :group => :development
gem 'bootstrap-sass'
gem 'cocoon'
gem 'simple_form'
gem 'acts-as-taggable-on'
gem 'haml'
gem 'sdoc',                 '0.4.0', group: :doc
gem 'omniauth-facebook'

group :development, :test do
  gem 'sqlite3'
end

group :production do
  gem 'pg',             '0.17.1'    #Needed for Heroku
  gem 'rails_12factor', '0.0.2'     #Needed for Heroku
end

Solution

It wasn't bundle update that was the problem. When I ran a scaffold it created scaffolds.css.scss that overrode my css. Deleted that and I'm good.