Mã code:

<center><h1>Changing Background Colours</h1>
<form>
<input type="text" name="color" size=18>
<select name=pco onChange="document.bgColor=(this.form.pco.value)">
<option value=aliceblue>aliceblue</option>
<option value=antiquewhite>antiquewhite</option>
<option value=aqua>aqua</option>
<option value=aquamarine>aquamarine</option>
<option value=azure>azure</option>
<option value=beige>beige</option>
<option value=bisque>bisque</option>
<option value=black>black</option>
<option value=blanchedalmond>blanchedalmond</option>
<option value=blue>blue</option>
<option value=blueviolet>blueviolet</option>
<option value=brown>brown</option>
<option value=burlywood>burlywood</option>
<option value=cadetblue>cadetblue</option>
<option value=chartreuse>chartreuse</option>
<option value=chocolate>chocolate</option>
<option value=coral>coral</option>
<option value=cornflowerblue>cornflowerblue</option>
<option value=cornsilk>cornsilk</option>
<option value=crimson>crimson</option>
<option value=cyan>cyan</option>
<option value=darkblue>darkblue</option>
<option value=darkcyan>darkcyan</option>
<option value=darkgoldenrod>darkgoldenrod</option>
<option value=darkgray>darkgray</option>
<option value=darkgreen>darkgreen</option>
<option value=darkkhaki>darkkhaki</option>
<option value=darkmagenta>darkmagenta</option>
<option value=darkolivegreen>darkolivegreen</option>
<option value=darkorange>darkorange</option>
<option value=darkorchid>darkorchid</option>
<option value=darkred>darkred</option>
<option value=darksalmon>darksalmon</option>
<option value=darkseagreen>darkseagreen</option>
<option value=darkslateblue>darkslateblue</option>
<option value=darkslategray>darkslategray</option>
<option value=darkturquoise>darkturquoise</option>
<option value=darkviolet>darkviolet</option>
<option value=deeppink>deeppink</option>
<option value=deepskyblue>deepskyblue</option>
<option value=dimgray>dimgray</option>
<option value=dodgerblue>dodgerblue</option>
<option value=firebrick>firebrick</option>
<option value=floralwhite>floralwhite</option>
<option value=forestgreen>forestgreen</option>
<option value=fuchsia>fuchsia</option>
<option value=gainsboro>gainsboro</option>
<option value=ghostwhite>ghostwhite</option>
<option value=gold>gold</option>
<option value=goldenrod>goldenrod</option>
<option value=gray>gray</option>
<option value=green>green</option>
<option value=greenyellow>greenyellow</option>
<option value=honeydew>honeydew</option>
<option value=hotpink>hotpink</option>
<option value=indianred>indianred</option>
<option value=indigo>indigo</option>
<option value=ivory>ivory</option>
<option value=khaki>khaki</option>
<option value=lavender>lavender</option>
<option value=lavenderblush>lavenderblush</option>
<option value=lawngreen>lawngreen</option>
<option value=lemonchiffon>lemonchiffon</option>
<option value=lightblue>lightblue</option>
<option value=lightcoral>lightcoral</option>
<option value=lightcyan>lightcyan</option>
<option value=lightgoldenrodyellow>lightgoldenrodyellow</option>
<option value=lightgreen>lightgreen</option>
<option value=lightgrey>lightgrey</option>
<option value=lightpink>lightpink</option>
<option value=lightsalmon>lightsalmon</option>
<option value=lightseagreen>lightseagreen</option>
<option value=lightskyblue>lightskyblue</option>
<option value=lightslategray>lightslategray</option>
<option value=lightsteelblue>lightsteelblue</option>
<option value=lightyellow>lightyellow</option>
<option value=lime>lime</option>
<option value=limegreen>limegreen</option>
<option value=linen>linen</option>
<option value=magenta>magenta</option>
<option value=maroon>maroon</option>
<option value=mediumaquamarine>mediumaquamarine</option>
<option value=mediumblue>mediumblue</option>
<option value=mediumorchid>mediumorchid</option>
<option value=mediumpurple>mediumpurple</option>
<option value=mediumseagreen>mediumseagreen</option>
<option value=mediumslateblue>mediumslateblue</option>
<option value=mediumspringgreen>mediumspringgreen</option>
<option value=mediumturquoise>mediumturquoise</option>
<option value=mediumvioletred>mediumvioletred</option>
<option value=midnightblue>midnightblue</option>
<option value=mintcream>mintcream</option>
<option value=mistyrose>mistyrose</option>
<option value=moccasin>moccasin</option>
<option value=navajowhite>navajowhite</option>
<option value=navy>navy</option>
<option value=oldlace>oldlace</option>
<option value=olive>olive</option>
<option value=olivedrab>olivedrab</option>
<option value=orange>orange</option>
<option value=orangered>orangered</option>
<option value=orchid>orchid</option>
<option value=palegoldenrod>palegoldenrod</option>
<option value=palegreen>palegreen</option>
<option value=paleturquoise>paleturquoise</option>
<option value=palevioletred>palevioletred</option>
<option value=papayawhip>papayawhip</option>
<option value=peachpuff>peachpuff</option>
<option value=peru>peru</option>
<option value=pink>pink</option>
<option value=plum>plum</option>
<option value=powderblue>powderblue</option>
<option value=purple>purple</option>
<option value=red>red</option>
<option value=rosybrown>rosybrown</option>
<option value=royalblue>royalblue</option>
<option value=saddlebrown>saddlebrown</option>
<option value=salmon>salmon</option>
<option value=sandybrown>sandybrown</option>
<option value=seagreen>seagreen</option>
<option value=seashell>seashell</option>
<option value=sienna>sienna</option>
<option value=silver>silver</option>
<option value=skyblue>skyblue</option>
<option value=slateblue>slateblue</option>
<option value=slategray>slategray</option>
<option value=snow>snow</option>
<option value=springgreen>springgreen</option>
<option value=steelblue>steelblue</option>
<option value=tan>tan</option>
<option value=teal>teal</option>
<option value=thistle>thistle</option>
<option value=tomato>tomato</option>
<option value=turquoise>turquoise</option>
<option value=violet>violet</option>
<option value=wheat>wheat</option>
<option value=white>white</option>
<option value=whitesmoke>whitesmoke</option>
<option value=yellow>yellow</option>
<option value=yellowgreen>yellowgreen</option>
</select>
<input type="button" value="Colour" onclick="document.bgColor=(this.form.color.value)">
<input type="reset" name="cancel" value="Reset">
</form></center>
<center><table border=2 cellpadding=5 cellspacing=3 width="90%">
<tr><td>
<font size="-1" color=navy>
aliceblue<br>
antiquewhite<br>
aqua<br>
aquamarine<br>
azure<br>
beige<br>
bisque<br>
black<br>
blanchedalmond<br>
blue<br>
blueviolet<br>
brown<br>
burlywood<br>
cadetblue<br>
chartreuse<br>
chocolate<br>
coral<br>
cornflowerblue<br>
cornsilk<br>
crimson<br>
cyan<br>
darkblue<br>
darkcyan<br>
darkgoldenrod<br>
darkgray<br>
darkgreen<br>
darkkhaki<br>
darkmagenta<br>
darkolivegreen<br>
darkorange<br>
darkorchid<br>
darkred<br>
darksalmon<br>
darkseagreen<br>
darkslateblue<br>
darkslategray<br>
darkturquoise<br>
darkviolet<br>
deeppink<br>
deepskyblue<br>
dimgray<br>
dodgerblue<br>
firebrick<br>
floralwhite<br>
forestgreen<br>
fuchsia<br>
</font>
</td>
<td>
<font size="-1" color=navy>
gainsboro<br>
ghostwhite<br>
gold<br>
goldenrod<br>
gray<br>
green<br>
greenyellow<br>
honeydew<br>
hotpink<br>
indianred<br>
indigo<br>
ivory<br>
khaki<br>
lavender<br>
lavenderblush<br>
lawngreen<br>
lemonchiffon<br>
lightblue<br>
lightcoral<br>
lightcyan<br>
lightgoldenrodyellow<br>
lightgreen<br>
lightgrey<br>
lightpink<br>
lightsalmon<br>
lightseagreen<br>
lightskyblue<br>
lightslategray<br>
lightsteelblue<br>
lightyellow<br>
lime<br>
limegreen<br>
linen<br>
magenta<br>
maroon<br>
mediumaquamarine<br>
mediumblue<br>
mediumorchid<br>
mediumpurple<br>
mediumseagreen<br>
mediumslateblue<br>
mediumspringgreen<br>
mediumturquoise<br>
mediumvioletred<br>
midnightblue<br>
mintcream<br>
mistyrose<br>
</font>
</td>
<td>
<font size="-1" color=navy>
moccasin<br>
navajowhite<br>
navy<br>
oldlace<br>
olive<br>
olivedrab<br>
orange<br>
orangered<br>
orchid<br>
palegoldenrod<br>
palegreen<br>
paleturquoise<br>
palevioletred<br>
papayawhip<br>
peachpuff<br>
peru<br>
pink<br>
plum<br>
powderblue<br>
purple<br>
red<br>
rosybrown<br>
royalblue<br>
saddlebrown<br>
salmon<br>
sandybrown<br>
seagreen<br>
seashell<br>
sienna<br>
silver<br>
skyblue<br>
slateblue<br>
slategray<br>
snow<br>
springgreen<br>
steelblue<br>
tan<br>
teal<br>
thistle<br>
tomato<br>
turquoise<br>
violet<br>
wheat<br>
white<br>
whitesmoke<br>
yellow<br>
yellowgreen<br>
</font>
</td></tr></table></center>