Redefine grayscale variables

Created by: sergiopantoja

Redefine grayscale variables

This would fix issue #21624 (closed) (I reverted $input-color-placeholder to #999 via the new $gray value).

This would also solve the #ddd issue discussed in #20677.

ORIGINAL

$gray-dark:                 #292b2c !default;
$gray:                      #464a4c !default;
$gray-light:                #636c72 !default;
$gray-lighter:              #eceeef !default;
$gray-lightest:             #f7f7f9 !default;

PROPOSED

$gray-darkest:              lighten(#000, 16%) !default;   // #292929
$gray-darker:               lighten(#000, 29%) !default;   // #4a4a4a
$gray-dark:                 lighten(#000, 40%) !default;   // #666666
$gray:                      lighten(#000, 60%) !default;   // #999999
$gray-light:                lighten(#000, 86.5%) !default; // #dddddd
$gray-lighter:              lighten(#000, 93.3%) !default; // #eeeeee
$gray-lightest:             lighten(#000, 96.8%) !default; // #f7f7f7

Most of these gray color changes seem like a close enough match to me, and the grays used for text still pass the contrast test related to issue #20952 (closed).

History

The grays were originally defined with lighten(), but this was changed in 2014 with commit https://github.com/twbs/bootstrap/commit/b50498acd4ac46eb5c0985bfc330b624bc8a6856#diff-a7693b847cd07d7aa4c819d11e5becc1

With v4, the grays were changed with this commit https://github.com/twbs/bootstrap/commit/76907b8b1ef86ea20b9041d9c7e655d6d566ff97