Various tricks to make borders look right in HTML:
1) Collapse table borders
By default, when you have borders, there appear to be gaps between each border. Putting the collapse syntax in your table gets rid of the gaps:
<table width=900 height=545 align=center style="border-collapse:collapse;">
2) Cell borders
If you want a border on only 1 side of a cell:
<td height=85 style=width:450px style="border-style: none none none solid; border-width: 3px; border-left-color:#5fb404;"
Note: the order of the "none none none solid" is: top right bottom left