_C_o_l_o_r _R_a_i_n_b_o_w_s
	
	     rainbow(n, s=1, v=1, start=0, end=(n-1)/n)
	
	_A_r_g_u_m_e_n_t_s:
	
	            n: the number of colors in the rainbow.
	
	          s,v: the ``saturation'' and ``value'' to be used
	               to complete the HSV color descriptions.
	
	        start: the (corrected) hue at which the rainbow
	               begins.
	
	          end: the (corrected) hue at which the rainbow
	               ends.
	
	_D_e_s_c_r_i_p_t_i_o_n:
	
	     This function creates a ``rainbow'' of n colors.
	     Equispaced hues in RGB space tend to cluster at the
	     red, green and blue primaries.  This function applies
	     an ad-hoc correction to diminish the effect of this
	     clustering, producing ``visually equispaced'' colors.
	
	     Some applications such as contouring require a pallette
	     of colors which do not ``wrap around'' to give a final
	     color close to the starting one.  The parameters start
	     and end can be used to specify particular subranges of
	     hues.  The following values can be used when generating
	     such a subrange: red=0, yellow=1/6, green=2/6,
	     cyan=3/6, blue=4/6 and magenta=5/6.
	
	     The values returned by rainbow can be used with a col=
	     specification in graphics functions or in par.
	
	_S_e_e _A_l_s_o:
	
	     rgb, hsv, gray.
	
	_E_x_a_m_p_l_e_s:
	
	     # A Color Wheel
	     piechart(rep(1,12), col=rainbow(12))