VimDiff doesn't work

[igrep]

I liked all of this colorscheme, except its DiffAdd and DiffChange!
I can't complete see what has changed and added... 😕
Do you have any idea how to modify?

About My Environment:
Arch Linux
Vim: 7.4.622
Terminal: mate-terminal 1.8.1

[w0ng]

What colours are in your ~/.Xresources?

Are you getting 256 colours in mate-terminal and vim?
Type tput colors in mate-terminal and :set t_Co in vim to confirm.

[igrep]

What colours are in your ~/.Xresources?

! https://gist.github.com/w0ng/3278077
! Hybrid Terminal Colours. Uses the palette from Tomorrow-Night:
! https://github.com/chriskempson/tomorrow-theme/blob/master/vim/colors/Tomorrow-Night.vim
! vim: ft=xdefaults

*background: #1D1F21
*foreground: #C5C8C6
! black
*color0: #282A2E
*color8: #373B41
! red
*color1: #A54242
*color9: #CC6666
! green
*color2: #8C9440
*color10: #B5BD68
! yellow
*color3: #DE935F
*color11: #F0C674
! blue
*color4: #5F819D
*color12: #81A2BE
! magenta
*color5: #85678F
*color13: #B294BB
! cyan
*color6: #5E8D87
*color14: #8ABEB7
! white
*color7: #707880
*color15: #C5C8C6

Are you getting 256 colours in mate-terminal and vim?
Type tput colors in mate-terminal and :set t_Co in vim to confirm.

$ tput colors
256

:set t_Co?
t_Co=256

[w0ng]

Is the regular vim theme working?
The vimdifff screenshot in the original theme isn't using hybrid

[igrep]

Is the regular vim theme working?

Yes. In koehler:

The vimdifff screenshot in the original theme isn't using hybrid

Yes I do. Same diff in hybrid: