Hover color

Dear Developer,

I have created a button using the following code:

[expand more_text=”Expand the Course” less_text=”Contract the Course” height=”0″ hide_less=”yes” text_color=”e0e0e0″ link_color=”#ffffff” link_style=”button” more_icon=”icon: angle-double-down” less_icon=”icon: angle-double-up”]Text goes here[/expand]

And the output as follows by a dropbox link:
https://www.dropbox.com/s/orcidong7fd1ts6/2015-08-21_16-36-19.jpg?dl=0

However, when I hover the mouse over the text or button, the hover color is grey instead of the website default hover color which is orange #e6670c.

Can you please show me how to change the hover color.

Thank you,

Imad Daou

https://ww.wp.xz.cn/plugins/shortcodes-ultimate/