Font color & line-break for JP on WP editor can't be seen on front-end

Dear Sir & Madam,

1. Current issue
Font color & line break for Japanese sentences on WP editor in WP admin
page has been shown as different color & no line break on front end.

2. My WP Environment
a)After I received my company website on WP 4.2.5 from web-developer,
I upgraded it to WP4.3.1 in WP admin page.
b)WP edit & Tiny MCE advanced have been installed as plugin.
c)Original setting of font color on base code is “White”
d)wp-config.php: define(‘DB_CHARSET’, ‘utf8mb4’) has already been set
e)Currently english words can be shown in White.
even though I change font color & line break for English sentenses
on WP editor, all these changes have been reflected on front end.
f)This phenomenon has happened for only Japanese sentences.
g)The base setting of Tiny MCE advanced is proper.
h)Japanese sentences has been copied from Excel file and
pasted to WP editor with using T button and line break has been done
with pressing shift + enter on WP editor.
i)Theme used for my company website is Jupitor.

How can I fix these issues so that font color & line break
defined for Japanese on WP editor can be perfectly reflected to front end page?

I need your help and am looking forward to getting your advices!
(So far,although I contacted 6 web-developers, nobody has found
the solution for these issues.)

Thank you & Best regards,
Mami & English Bulldog