<s>
Redshift	B-Application
is	O
an	O
application	O
that	O
adjusts	O
the	O
computer	B-Device
display	I-Device
's	O
color	O
temperature	O
based	O
upon	O
the	O
time	O
of	O
day	O
.	O
</s>
<s>
The	O
program	O
is	O
free	B-Application
software	I-Application
,	O
and	O
is	O
intended	O
to	O
reduce	O
eye	O
strain	O
as	O
well	O
as	O
insomnia	O
(	O
see	O
Sleep	O
#Circadian	O
clock	O
and	O
Phase	O
response	O
curve	O
#Light	O
)	O
.	O
</s>
<s>
Redshift	B-Application
transitions	O
the	O
computer	B-Device
display	I-Device
's	O
color	O
temperature	O
evenly	O
between	O
daytime	B-Application
and	O
night	O
temperatures	O
to	O
allow	O
the	O
user	O
's	O
eyes	O
to	O
slowly	O
adapt	O
.	O
</s>
<s>
Typical	O
color	O
temperature	O
during	O
the	O
daytime	B-Application
is	O
5500	O
–	O
6500	O
K	O
.	O
</s>
<s>
Redshift	B-Application
is	O
primarily	O
distributed	O
for	O
and	O
used	O
on	O
the	O
Linux	B-Application
operating	I-Application
system	I-Application
.	O
</s>
<s>
Redshift	B-Application
can	O
be	O
used	O
to	O
set	O
a	O
single	O
color	O
temperature	O
and	O
brightness	O
(	O
"	O
one	O
shot	O
mode	O
"	O
)	O
or	O
can	O
adjust	O
the	O
temperature	O
and	O
brightness	O
continuously	O
to	O
follow	O
the	O
sun	O
's	O
elevation	O
,	O
in	O
which	O
case	O
it	O
will	O
transition	O
to	O
the	O
night	O
color	O
temperature	O
settings	O
near	O
twilight	O
.	O
</s>
<s>
The	O
temperature	O
and	O
brightness	O
settings	O
for	O
daytime	B-Application
and	O
night	O
can	O
be	O
user-configured	O
.	O
</s>
<s>
On	O
Linux	B-Application
and	O
BSD	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
,	O
Redshift	B-Application
supports	O
multiple	O
monitors	O
through	O
the	O
X	B-Operating_System
extensions	O
RandR	O
(	O
preferred	O
)	O
or	O
VidMode	O
,	O
or	O
through	O
the	O
Direct	B-Application
Rendering	I-Application
Manager	I-Application
.	O
</s>
<s>
Because	O
Redshift	B-Application
can	O
only	O
be	O
configured	O
to	O
use	O
the	O
same	O
gamma	O
correction	O
on	O
all	O
monitors	O
it	O
controls	O
,	O
it	O
is	O
usually	O
desirable	O
to	O
run	O
one	O
instance	O
of	O
the	O
program	O
per	O
monitor	O
.	O
</s>
<s>
Redshift	B-Application
originally	O
possessed	O
only	O
a	O
command-line	B-Application
interface	I-Application
,	O
but	O
now	O
has	O
graphical	B-Application
user	I-Application
interfaces	I-Application
(	O
GUIs	B-Application
)	O
that	O
support	O
most	O
Linux	B-Application
desktop	O
environments	O
.	O
</s>
<s>
Those	O
GUIs	B-Application
include	O
redshift-gtk	O
,	O
redshift-plasmoid	O
,	O
and	O
nightshift	O
.	O
</s>
<s>
redshift-gtk	O
is	O
included	O
in	O
Redshift	B-Application
's	O
source	O
tree	O
.	O
</s>
<s>
In	O
addition	O
to	O
a	O
windowed	O
interface	O
,	O
it	O
provides	O
a	O
tray	O
status	O
icon	O
that	O
can	O
enable	O
or	O
disable	O
Redshift	B-Application
or	O
adjust	O
the	O
screen	O
's	O
color	O
temperature	O
automatically	O
.	O
</s>
<s>
Redshift	B-Application
can	O
be	O
opened	O
with	O
the	O
use	O
of	O
terminal	O
,	O
panel	O
launchers	O
or	O
startup	O
commands	O
:	O
the	O
command	O
'	O
redshift	B-Application
-O	O
#TEMP	O
'	O
(	O
#TEMP	O
being	O
a	O
number	O
from	O
1000	O
to	O
25000	O
)	O
will	O
set	O
the	O
temperature	O
and	O
the	O
command	O
'	O
redshift	B-Application
-x	O
'	O
to	O
exit	O
Redshift	B-Application
.	O
</s>
<s>
Change	O
the	O
properties	O
of	O
the	O
file	O
so	O
it	O
can	O
be	O
executed	O
(	O
using	O
chmod	B-Application
or	O
context	O
menu	O
permissions	O
)	O
.	O
</s>
<s>
Create	O
a	O
new	O
launcher	O
(	O
"	O
exit	O
redshift	B-Application
"	O
)	O
with	O
the	O
command	O
redshift	B-Application
-x	O
(	O
no	O
need	O
to	O
open	O
this	O
in	O
terminal	O
)	O
.	O
</s>
<s>
Use	O
the	O
launcher	O
to	O
set	O
temperature	O
or	O
exit	O
Redshift	B-Application
.	O
</s>
<s>
Redshift	B-Application
has	O
been	O
positively	O
reviewed	O
by	O
Linux	B-Application
users	O
,	O
who	O
note	O
that	O
Redshift	B-Application
has	O
some	O
installation	O
and	O
user	O
interface	O
advantages	O
compared	O
to	O
the	O
f.lux	B-Operating_System
Linux	B-Application
port	O
xflux	B-Operating_System
.	O
</s>
<s>
However	O
,	O
f.lux	B-Operating_System
'	O
s	O
systems	O
have	O
since	O
been	O
updated	O
to	O
enhance	O
its	O
dimmed	O
display	O
.	O
</s>
<s>
Ubuntu	O
MATE	O
provides	O
Redshift	B-Application
installed	O
by	O
default	O
since	O
their	O
17.10	O
release	O
.	O
</s>
<s>
Linux	B-Application
Mint	I-Application
Cinnamon	I-Application
provides	O
Redshift	B-Application
installed	O
by	O
default	O
since	O
their	O
18.3	O
release	O
.	O
</s>
