For quick reference sake, here is a table with hex codes for a wide range of grays from White to Black. It should assist when you are needing to pick a color for text or backgrounds.
There is a complimentary color hex code chart here.
| ffffff | fefefe | fdfdfd | fcfcfc | fbfbfb | fafafa | f9f9f9 | f8f8f8 | f7f7f7 | f6f6f6 | f5f5f5 | f4f4f4 | f3f3f3 | f2f2f2 | f1f1f1 | f0f0f0 |
| efefef | eeeeee | ededed | ececec | ebebeb | eaeaea | e9e9e9 | e8e8e8 | e7e7e7 | e6e6e6 | e5e5e5 | e4e4e4 | e3e3e3 | e2e2e2 | e1e1e1 | e0e0e0 |
| dfdfdf | dedede | dddddd | dcdcdc | dbdbdb | dadada | d9d9d9 | d8d8d8 | d7d7d7 | d6d6d6 | d5d5d5 | d4d4d4 | d3d3d3 | d2d2d2 | d1d1d1 | d0d0d0 |
| cfcfcf | cecece | cdcdcd | cccccc | cbcbcb | cacaca | c9c9c9 | c8c8c8 | c7c7c7 | c6c6c6 | c5c5c5 | c4c4c4 | c3c3c3 | c2c2c2 | c1c1c1 | c0c0c0 |
| bfbfbf | bebebe | bdbdbd | bcbcbc | bbbbbb | bababa | b9b9b9 | b8b8b8 | b7b7b7 | b6b6b6 | b5b5b5 | b4b4b4 | b3b3b3 | b2b2b2 | b1b1b1 | b0b0b0 |
| afafaf | aeaeae | adadad | acacac | ababab | aaaaaa | a9a9a9 | a8a8a8 | a7a7a7 | a6a6a6 | a5a5a5 | a4a4a4 | a3a3a3 | a2a2a2 | a1a1a1 | a0a0a0 |
| 9f9f9f | 9e9e9e | 9d9d9d | 9c9c9c | 9b9b9b | 9a9a9a | 999999 | 989898 | 979797 | 969696 | 959595 | 949494 | 939393 | 929292 | 919191 | 909090 |
| 8f8f8f | 8e8e8e | 8d8d8d | 8c8c8c | 8b8b8b | 8a8a8a | 898989 | 888888 | 878787 | 868686 | 858585 | 848484 | 838383 | 828282 | 818181 | 808080 |
| 7f7f7f | 7e7e7e | 7d7d7d | 7c7c7c | 7b7b7b | 7a7a7a | 797979 | 787878 | 777777 | 767676 | 757575 | 747474 | 737373 | 727272 | 717171 | 707070 |
| 6f6f6f | 6e6e6e | 6d6d6d | 6c6c6c | 6b6b6b | 6a6a6a | 696969 | 686868 | 676767 | 666666 | 656565 | 646464 | 636363 | 626262 | 616161 | 606060 |
| 5f5f5f | 5e5e5e | 5d5d5d | 5c5c5c | 5b5b5b | 5a5a5a | 595959 | 585858 | 575757 | 565656 | 555555 | 545454 | 535353 | 525252 | 515151 | 505050 |
| 4f4f4f | 4e4e4e | 4d4d4d | 4c4c4c | 4b4b4b | 4a4a4a | 494949 | 484848 | 474747 | 464646 | 454545 | 444444 | 434343 | 424242 | 414141 | 404040 |
| 3f3f3f | 3e3e3e | 3d3d3d | 3c3c3c | 3b3b3b | 3a3a3a | 393939 | 383838 | 373737 | 363636 | 353535 | 343434 | 333333 | 323232 | 313131 | 303030 |
| 2f2f2f | 2e2e2e | 2d2d2d | 2c2c2c | 2b2b2b | 2a2a2a | 292929 | 282828 | 272727 | 262626 | 252525 | 242424 | 232323 | 222222 | 212121 | 202020 |
| 1f1f1f | 1e1e1e | 1d1d1d | 1c1c1c | 1b1b1b | 1a1a1a | 191919 | 181818 | 171717 | 161616 | 151515 | 141414 | 131313 | 121212 | 111111 | 101010 |
| 0f0f0f | 0e0e0e | 0d0d0d | 0c0c0c | 0b0b0b | 0a0a0a | 090909 | 080808 | 070707 | 060606 | 050505 | 040404 | 030303 | 020202 | 010101 | 000000 |