Please be advised that, as of now, BuddyBoss does not have an out-of-the-box option for this.
Modifications are generally considered custom work; however, we are making an exception in this case. Kindly review our Support Policy here: https://www.buddyboss.com/support-policy/.
Please try adding the following CSS code. Feel free to adjust the color value to match your preferences.
1. Go to BuddyBoss > Theme Options
2. Under Custom Codes, enable CSS
3. Append the following:
span.like-count.reactions_item {color: #0029ff !important;}
4. Save Changes