I've displayed here the 216 colors in the Web Pallette. These colors appear the same on any platform. Many platforms translate other hexideximal colors to the nearest one on this list.
Here's a test of whether your computer can distinguish among the web palette color and the nearby colors:
| #99ccff | #89bbef | #9abcfe | #9accfe | #99dbfe | #88bdee |
| #000000 | #000033 | #000066 | #000099 | #0000cc | #0000ff |
| #003300 | #003333 | #003366 | #003399 | #0033cc | #0033ff |
| #006600 | #006633 | #006666 | #006699 | #0066cc | #0066ff |
| #009900 | #009933 | #009966 | #009999 | #0099cc | #0099ff |
| #00cc00 | #00cc33 | #00cc66 | #00cc99 | #00cccc | #00ccff |
| #00ff00 | #00ff33 | #00ff66 | #00ff99 | #00ffcc | #00ffff |
| #330000 | #330033 | #330066 | #330099 | #3300cc | #3300ff |
| #333300 | #333333 | #333366 | #333399 | #3333cc | #3333ff |
| #336600 | #336633 | #336666 | #336699 | #3366cc | #3366ff |
| #339900 | #339933 | #339966 | #339999 | #3399cc | #3399ff |
| #33cc00 | #33cc33 | #33cc66 | #33cc99 | #33cccc | #33ccff |
| #33ff00 | #33ff33 | #33ff66 | #33ff99 | #33ffcc | #33ffff |
| #660000 | #660033 | #660066 | #660099 | #6600cc | #6600ff |
| #663300 | #663333 | #663366 | #663399 | #6633cc | #6633ff |
| #666600 | #666633 | #666666 | #666699 | #6666cc | #6666ff |
| #669900 | #669933 | #669966 | #669999 | #6699cc | #6699ff |
| #66cc00 | #66cc33 | #66cc66 | #66cc99 | #66cccc | #66ccff |
| #66ff00 | #66ff33 | #66ff66 | #66ff99 | #66ffcc | #66ffff |
| #990000 | #990033 | #990066 | #990099 | #9900cc | #9900ff |
| #993300 | #993333 | #993366 | #993399 | #9933cc | #9933ff |
| #996600 | #996633 | #996666 | #996699 | #9966cc | #9966ff |
| #999900 | #999933 | #999966 | #999999 | #9999cc | #9999ff |
| #99cc00 | #99cc33 | #99cc66 | #99cc99 | #99cccc | #99ccff |
| #99ff00 | #99ff33 | #99ff66 | #99ff99 | #99ffcc | #99ffff |
| #cc0000 | #cc0033 | #cc0066 | #cc0099 | #cc00cc | #cc00ff |
| #cc3300 | #cc3333 | #cc3366 | #cc3399 | #cc33cc | #cc33ff |
| #cc6600 | #cc6633 | #cc6666 | #cc6699 | #cc66cc | #cc66ff |
| #cc9900 | #cc9933 | #cc9966 | #cc9999 | #cc99cc | #cc99ff |
| #cccc00 | #cccc33 | #cccc66 | #cccc99 | #cccccc | #ccccff |
| #ccff00 | #ccff33 | #ccff66 | #ccff99 | #ccffcc | #ccffff |
| #ff0000 | #ff0033 | #ff0066 | #ff0099 | #ff00cc | #ff00ff |
| #ff3300 | #ff3333 | #ff3366 | #ff3399 | #ff33cc | #ff33ff |
| #ff6600 | #ff6633 | #ff6666 | #ff6699 | #ff66cc | #ff66ff |
| #ff9900 | #ff9933 | #ff9966 | #ff9999 | #ff99cc | #ff99ff |
| #ffcc00 | #ffcc33 | #ffcc66 | #ffcc99 | #ffcccc | #ffccff |
| #ffff00 | #ffff33 | #ffff66 | #ffff99 | #ffffcc | #ffffff |