Color and PyfaceColor Documentation

[corranwebster]

Add documentation for the Color class and PyfaceColor trait.

[codecov-commenter]

Codecov Report

Merging #710 into master will increase coverage by 0.76%.
The diff coverage is 93.33%.

@@            Coverage Diff             @@
##           master     #710      +/-   ##
==========================================
+ Coverage   39.76%   40.53%   +0.76%     
==========================================
  Files         493      502       +9     
  Lines       27259    27614     +355     
  Branches     4140     4185      +45     
==========================================
+ Hits        10840    11193     +353     
- Misses      15944    15950       +6     
+ Partials      475      471       -4     

Impacted Files	Coverage Δ
pyface/ui/qt4/data_view/data_view_item_model.py	49.30% <38.46%> (-0.70%)	⬇️
pyface/ui/wx/data_view/data_wrapper.py	86.36% <86.36%> (ø)
pyface/data_view/i_data_wrapper.py	88.46% <88.46%> (ø)
...face/data_view/data_models/row_table_data_model.py	91.25% <91.25%> (ø)
pyface/ui_traits.py	86.11% <93.93%> (+2.32%)	⬆️
pyface/data_view/value_types/color_value.py	95.45% <95.45%> (ø)
pyface/color.py	100.00% <100.00%> (ø)
pyface/data_view/abstract_value_type.py	97.72% <100.00%> (+0.29%)	⬆️
pyface/data_view/data_models/data_accessors.py	100.00% <100.00%> (ø)
pyface/data_view/data_wrapper.py	100.00% <100.00%> (ø)
... and 22 more

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[rahulporuri]

LGTM with one small correction. Haven't tested the built docs though.

[rahulporuri]

Suggested change

	representation is important. This is particularly so when you want to allow
	representation is important. This is particularly important when you want to allow

[corranwebster]

I think I prefer the "so" - it references pack to the "important" in the previous sentence without repeating the word.