code: def scale_color_grey(
      start=None,
      end=None,
      name=None,
      breaks=None,
      labels=None,
      lablim=None,
      limits=None,
      na_value=None,
      guide=None,
      trans=None,
      format=None,
  ):
      """
      Sequential grey color scale for `color` aesthetic.
  
      Parameters
      ----------
      start : float
          Gray value at low end of palette in range [0, 1].
      end : float
          Gray value at high end of palette in range [0, 1].
      name : str
          The name of the scale - used as the axis label or the legend title.
          If None, the default, the name of the scale
          is taken from the first mapping used for that aesthetic.
      breaks : list or dict
          A list of data values specifying the positions of ticks, or a dictionary which maps the tick labels to the breaks values.
      labels : list of str or dict
          A list of labels on ticks, or a dictionary which maps the breaks values to the tick labels.
      lablim : int, default=None
          The maximum label length (in characters) before trimming is applied.
      limits : list
          Continuous scale: a numeric vector of length two providing limits of the scale.
          Discrete scale: a vector specifying the data range for the scale
          and the default order of their display in guides.
      na_value
          Missing values will be replaced with this value.
      guide
          Guide to use for this scale. It can either be a string ('colorbar', 'legend')
          or a call to a guide function (`guide_colorbar()`, `guide_legend()`)
          specifying additional arguments. 'none' will hide the guide.
      trans : {'identity', 'log10', 'log2', 'symlog', 'sqrt', 'reverse'}
          Name of built-in transformation.
      format : str
          Define the format for labels on the scale. The syntax resembles Python's:
  
          - '.2f' -> '12.45'
          - 'Num {}' -> 'Num 12.456789'
          - 'TTL: {.2f}$' -> 'TTL: 12.45$'
  
          For more info see https://lets-plot.org/pages/formats.html.
  
      Returns
      -------
      `FeatureSpec`
          Scale specification.
  
      Notes
      -----
      Define sequential grey color scale for `color` aesthetic.
  
      Examples
      --------
      .. jupyter-execute::
          :linenos:
          :emphasize-lines: 6
  
          from lets_plot import *
          LetsPlot.setup_html()
          x = list(range(50))
          ggplot({'x': x}, aes(x='x')) + \\
              geom_tile(aes(color='x'), fill='white', size=3) + \\
              scale_color_grey(start=.7, end=.2) + \\
              coord_cartesian() + \\
              ggsize(600, 200)
  
      """
      return scale_grey(
          "color",
          start=start,
          end=end,
          name=name,
          breaks=breaks,
          labels=labels,
          lablim=lablim,
          limits=limits,
          na_value=na_value,
          guide=guide,
          trans=trans,
          format=format,
      )
  
imports: from .core import FeatureSpec, FeatureSpecArray
  from .util import as_boolean
label_desc: Use image node_id 29 for calling a global function with example usage: scale_color_grey(start, end, name, breaks, labels, lablim, limits, na_value, guide, trans, format) and returns: scale_grey