RGB to Hexadecimal Color Conversion
Setting a safe color is simply a matter of selecting a combination of safe hex values. In this case, #9966FF is a safe hex color; #9370DB is not. Most Web design tools like Macromedia Dreamweaver contain safe color pickers; so do imaging tools like Macromedia Fireworks or Adobe PhotoShop. Designers looking for color palettes, including improved color pickers and swatches, should visit http://www.visibone.com/colorlab/.
Setting an unsafe color to its nearest safe color is fairly easy—just round each particular red, green or blue value up or down to the nearest safe value. A complete conversion of hex to decimal values is shown in Table E-2. Safe values are indicated in bold.
| 00=00 | 01=01 | 02=02 | 03=03 | 04=04 | 05=05 |
| 06=06 | 07=07 | 08=08 | 09=09 | 10=0A | 11=0B |
| 12=0C | 13=0D | 14=0E | 15=0F | 16=10 | 17=11 |
| 18=12 | 19=13 | 20=14 | 21=15 | 22=16 | 23=17 |
| 24=18 | 25=19 | 26=1A | 27=1B | 28=1C | 29=1D |
| 30=1E | 31=1F | 32=20 | 33=21 | 34=22 | 35=23 |
| 36=24 | 37=25 | 38=26 | 39=27 | 40=28 | 41=29 |
| 42=2A | 43=2B | 44=2C | 45=2D | 46=2E | 47=2F |
| 48=30 | 49=31 | 50=32 | 51=33 | 52=34 | 53=35 |
| 54=36 | 55=37 | 56=38 | 57=39 | 58=3A | 59=3B |
| 60=3C | 61=3D | 62=3E | 63=3F | 64=40 | 65=41 |
| 66=42 | 67=43 | 68=44 | 69=45 | 70=46 | 71=47 |
| 72=48 | 73=49 | 74=4A | 75=4B | 76=4C | 77=4D |
| 78=4E | 79=4F | 80=50 | 81=51 | 82=52 | 83=53 |
| 84=54 | 85=55 | 86=56 | 87=57 | 88=58 | 89=59 |
| 90=5A | 91=5B | 92=5C | 93=5D | 94=5E | 95=5F |
| 96=60 | 97=61 | 98=62 | 99=63 | 100=64 | 101=65 |
| 102=66 | 103=67 | 104=68 | 105=69 | 106=6A | 107=6B |
| 108=6C | 109=6D | 110=6E | 111=6F | 112=70 | 113=71 |
| 114=72 | 115=73 | 116=74 | 117=75 | 118=76 | 119=77 |
| 120=78 | 121=79 | 122=7A | 123=7B | 124=7C | 125=7D |
| 126=7E | 127=7F | 128=80 | 129=81 | 130=82 | 131=83 |
| 132=84 | 133=85 | 134=86 | 135=87 | 136=88 | 137=89 |
| 138=8A | 139=8B | 140=8C | 141=8D | 142=8E | 143=8F |
| 144=90 | 145=91 | 146=92 | 147=93 | 148=94 | 149=95 |
| 150=96 | 151=97 | 152=98 | 153=99 | 154=9A | 155=9B |
| 156=9C | 157=9D | 158=9E | 159=9F | 160=A0 | 161=A1 |
| 162=A2 | 163=A3 | 164=A4 | 165=A5 | 166=A6 | 167=A7 |
| 168=A8 | 169=A9 | 170=AA | 171=AB | 172=AC | 173=AD |
| 174=AE | 175=AF | 176=B0 | 177=B1 | 178=B2 | 179=B3 |
| 180=B4 | 181=B5 | 182=B6 | 183=B7 | 184=B8 | 185=B9 |
| 186=BA | 187=BB | 188=BC | 189=BD | 190=BE | 191=BF |
| 192=C0 | 193=C1 | 194=C2 | 195=C3 | 196=C4 | 197=C5 |
| 198=C6 | 199=C7 | 200=C8 | 201=C9 | 202=CA | 203=CB |
| 204=CC | 205=CD | 206=CE | 207=CF | 208=D0 | 209=D1 |
| 210=D2 | 211=D3 | 212=D4 | 213=D5 | 214=D6 | 215=D7 |
| 216=D8 | 217=D9 | 218=DA | 219=DB | 220=DC | 221=DD |
| 222=DE | 223=DF | 224=E0 | 225=E1 | 226=E2 | 227=E3 |
| 228=E4 | 229=E5 | 230=E6 | 231=E7 | 232=E8 | 233=E9 |
| 234=EA | 235=EB | 236=EC | 237=ED | 238=EE | 239=EF |
| 240=F0 | 241=F1 | 242=F2 | 243=F3 | 244=F4 | 245=F5 |
| 246=F6 | 247=F7 | 248=F8 | 249=F9 | 250=FA | 251=FB |
| 252=FC | 253=FD | 254=FE | 255=FF |
Although mathematically translating to the closest browser-safe color seems appropriate, it might not look correct to many people. Consider creating a hybrid color by combining multiple safe colors together. This is done simply by creating a checkerboard effect with a GIF image, in which two or more non-dithering colors are placed side by side to give the appearance of a third color. A variety of PhotoShop plug-ins such as Colorsafe (www.boxtopsoft.com) exist for mixing colors.
Next: Color Names and Numerical Equivalents
