Changing the color od the category count in modern theme at the homepage is very easy. We are going to change the following :

We are working on the lines 55 and 59 of main.php (oc-content/themes/modern/main.php)

Line 55 (a little part of it)

<span>(<?php echo osc_category_total_items() ; ?>)</span>

Change it to

<span class="parent_cat_total_items">(<?php echo osc_category_total_items() ; ?>)</span>

Line 59

<span>(<?php echo osc_category_total_items() ; ?>)</span>

change it to

<span class="sub_cat_total_items">(<?php echo osc_category_total_items() ; ?>)</span>

Open the file (located at oc-content/themes/modern/css/style.css) Add the following lines at the end of the file

.home #main .categories .category span.parent_cat_total_items { color:red;}
span.sub_cat_total_items { color:blue;}

Replace red and blue with the colors you want.