Hi BlueYatri,
Some good hints can be found at here regarding styling the box alignment and border colors.
How would you like to align your text boxes? Something different than left aligned?
To address your second question, I believe you would be able to change the text box borders to black by editing your child theme’s CSS file depending on what theme you are using.
For example, when I use the Twenty Twelve theme, I know I can edit the style.css file within that theme and locate the setting below marked in bold. Below I changed the color value from gray to black…or… from #ccc to #000 as illustrated below.
/* Form fields, general styles first */
button,
input,
select,
textarea {
border: 1px solid #000;
border-radius: 3px;
font-family: inherit;
padding: 6px;
padding: 0.428571429rem;
}
Hopefully this makes sense. Let me know how it goes.