I am one of your reseller, I do provide hosting for schools, colleges and various institutions. I have my website in which I have provided the hosting link from which these users can signup for their Account.
But, there is one problem, the color scheme of my website is different from the color scheme of the control panel, It looks un-professional.

You need to change the control panel design and color, so that there becomes similarity between your website and the control panel. For this get logged in your control panel.
In the Left menu, there is Look and Feel Option, click on that and then click on the design settings. In the Left menu, what you are viewing is the present theme, click on the Modify button. When you make a theme available to your customers, you are able to specify the default theme for their control panel. Left menu is the only theme which you cannot disable as an option.
Now you can try out the different combinations of colors, images and icons, until you find the look you like.