r.colors(1)	       Grass User's Manual	      r.colors(1)



NNAAMMEE
       _r_._c_o_l_o_r_s  -  Creates/Modifies  the  color table associated
       with a raster map layer.

       _(_G_R_A_S_S _R_a_s_t_e_r _P_r_o_g_r_a_m_)

SSYYNNOOPPSSIISS
       rr..ccoolloorrss

       rr..ccoolloorrss hheellpp

       rr..ccoolloorrss [--wwqq] mmaapp==_n_a_m_e [ccoolloorr==_t_y_p_e] [rraasstt_=_n_a_m_e]

DDEESSCCRRIIPPTTIIOONN
       _r_._c_o_l_o_r_s allows the user to create and/or modify the color
       table  for a raster map layer. The map layer (specified on
       the command line by mmaapp==_n_a_m_e) must  exist  in  the  user's
       current	mapset	search path. The color table specified by
       ccoolloorr==_t_y_p_e must be one of the following:

	    color type	  description
	    aspect	  (aspect oriented grey colors)
	    grey	  (grey scale)
	    grey.eq	  (histogram-equalized grey scale)
	    grey.log	  (histogram logarithmic transformed grey
       scale)
	    byr 	  (blue through yellow to red colors)
	    gyr 	  (green through yellow to red colors)
	    rainbow	  (rainbow color table)
	    ramp	  (color ramp)
	    random	  (random color table)
	    ryg 	  (red through yellow to green colors)
	    wave	  (color wave)
	    rules	   (create new color table based on user-
       specified rules)

       If the user specifies the --ww flag, the current color table
       file for the input map will not be overwritten. This means
       that the color table is created only if the _m_a_p	does  not
       already	have  a color table. If this option is not speci-
       fied, the color table will be  created  if  one	does  not
       exist, or modified if it does.

       If  the	user sets the --qq flag, _r_._c_o_l_o_r_s will run quietly,
       Without printing numerous  messages  on	its  progress  to
       standard output.

       Color  table types _a_s_p_e_c_t_, _g_r_e_y_, _g_r_e_y_._e_q (histogram-equal-
       ized grey scale), _b_y_r (blue-yellow-red),  _g_y_r  (green-yel-
       low-red),  _r_a_i_n_b_o_w_,  _r_a_m_p_, _r_y_g (red-yellow-green), _r_a_n_d_o_m,
       and _w_a_v_e are pre-defined color tables that _r_._c_o_l_o_r_s  knows
       how to create without any further input.

       The  _r_u_l_e_s  color  table  type will cause _r_._c_o_l_o_r_s to read
       color table specifications from standard input (stdin) and
       will build the color table accordingly.

       Using  color  table  type  _r_u_l_e_s,  there are three ways to
       build a color table: by color list,  by	category  values,
       and by "percent" values.

       Building  a  customized	color  table by color list is the
       simplest of the three rules methods: just list the  colors
       you  wish  to  appear in the color table in the order that
       you wish them to appear.  Use  the  standard  GRASS  color
       names:  white,  black,  red, green, blue, yellow, magenta,
       cyan, aqua, grey, gray, orange, brown, purple, violet, and
       indigo.

       For  example,  to  create a color table for the raster map
       layer _e_l_e_v_a_t_i_o_n that assigns greens to  low  map  category
       values, browns to the next larger map category values, and
       yellows to the still larger map category values, one would
       type:

       rr..ccoolloorrss mmaapp==_e_l_e_v_a_t_i_o_n ccoolloorr==_r_u_l_e_s

       green

       brown

       yellow

       end

       To  build  a  color table by category values' indices, the
       user should determine the range of category values in  the
       raster  map layer with which the color table will be used.
       Specific category values will then be associated with spe-
       cific  colors.  Note  that  a  color  does  not have to be
       assigned for every valid category value	because  _r_._c_o_l_o_r_s
       will interpolate a color ramp to fill in where color spec-
       ification rules have been left out. The format of  such	a
       specification is as follows:

       ccaatteeggoorryy__vvaalluuee ccoolloorr__nnaammee

       ccaatteeggoorryy__vvaalluuee ccoolloorr__nnaammee



       ccaatteeggoorryy__vvaalluuee ccoolloorr__nnaammee

       eenndd

       Each  category  value  must  be	valid  for the raster map
       layer, category values must be in ascending order and only
       use standard GRASS color names (see above).

       Colors  can also be specified by color numbers each in the
       range 0-255.  The format of a category value  color  table
       specification  using  color numbers instead of color names
       is as follows:

       ccaatteeggoorryy__vvaalluuee rreedd__nnuummbbeerr ggrreeeenn__nnuummbbeerr bblluuee__nnuummbbeerr

       ccaatteeggoorryy__vvaalluuee rreedd__nnuummbbeerr ggrreeeenn__nnuummbbeerr bblluuee__nnuummbbeerr



       ccaatteeggoorryy__vvaalluuee rreedd__nnuummbbeerr ggrreeeenn__nnuummbbeerr bblluuee__nnuummbbeerr

       eenndd

       Specifying a color table by "percent" values allows one to
       treat  a color table as if it were numbered from 0 to 100.
       The format of a "percent" value color table  specification
       is  the	same as for a category value color specification,
       except that the category values are replaced by	"percent"
       values, each from 0-100, in ascending order. The format is
       as follows:

       ppeerrcceenntt__vvaalluuee%% ccoolloorr__nnaammee

       ppeerrcceenntt__vvaalluuee%% ccoolloorr__nnaammee



       ppeerrcceenntt__vvaalluuee%% ccoolloorr__nnaammee

       eenndd

       Using "percent" value  color  table  specification  rules,
       colors  can also be specified by color numbers each in the
       range 0-255. The format of a  percent  value  color  table
       specification  using  color numbers instead of color names
       is as follows:

       ppeerrcceenntt__vvaalluuee%% rreedd__nnuummbbeerr ggrreeeenn__nnuummbbeerr bblluuee__nnuummbbeerr

       ppeerrcceenntt__vvaalluuee%% rreedd__nnuummbbeerr ggrreeeenn__nnuummbbeerr bblluuee__nnuummbbeerr



       ppeerrcceenntt__vvaalluuee%% rreedd__nnuummbbeerr ggrreeeenn__nnuummbbeerr bblluuee__nnuummbbeerr

       eenndd

       Note that you can also mix these three  methods	of  color
       table specification; for example:

       00 bbllaacckk

       1100%% yyeellllooww

       7788 bblluuee

       mmaaggeennttaa

       ppuurrppllee

       bbrroowwnn

       110000%% 00 225555 223300

       eenndd

EEXXAAMMPPLLEESS
	      The  below example shows how you can specify colors
	      for a three category map, assigning red to category
	      1,  green  to  category  2, and blue to category 3.
	      Start by using a text editor, like  _v_i,  to  create
	      the  following  rules  specification  file. Save it
	      with the name _r_u_l_e_s_._f_i_l_e.


       11 rreedd

       22 ggrreeeenn

       33 bblluuee

       eenndd

       The color table can then by assigned to map  _t_h_r_e_e_c_a_t_s  by
       typing  the  following  command	at the GRASS> prompt: ccaatt
       rruulleess..ffiillee || rr..ccoolloorrss mmaapp==_t_h_r_e_e_c_a_t_s ccoolloorr==_r_u_l_e_s


	      To create a natural looking LUT for true map  layer
	      _e_l_e_v_a_t_i_o_n,  use  the  following rules specification
	      file. It will assign  light  green  shades  to  the
	      lower  elevations  (first 20% of the LUT), and then
	      darker greens (next 15%, and next  20%)  and  light
	      browns (next 20%) for middle elevations, and darker
	      browns  (next  15%)  for	higher	elevations,   and
	      finally  yellow  for the highest peaks (last 10% of
	      LUT).  0% 0 230 0

	      20% 0 160 0

	      35% 50 130 0

	      55% 120 100 30

	      75% 120 130 40

	      90% 170 160 50


       Option rraasstt allows user to specify a raster map _n_a_m_e  from
       which to copy the color map.

SSEEEE AALLSSOO
       _d_._c_o_l_o_r_m_o_d_e

       _d_._c_o_l_o_r_s

       _d_._c_o_l_o_r_t_a_b_l_e

       _d_._d_i_s_p_l_a_y

       _d_._l_e_g_e_n_d

       _p_._c_o_l_o_r_s

       _r_._s_u_p_p_o_r_t

AAUUTTHHOORRSS
       Michael Shapiro and David Johnson

       _L_a_s_t _c_h_a_n_g_e_d_: _$_D_a_t_e_: _2_0_0_2_/_0_4_/_2_2 _1_3_:_0_9_:_1_5 _$



GRASS 5.0					      r.colors(1)
