Prevent overlapped areas between opaque boxes from darkening

I'm having trouble darkening the areas where opaque boxes overlap.

I know that it can be solved by inserting new line(\n) into middle sentence. But I'm finding the way of solve it by only manipulating color.

Can anyone help me to solve it?

Screenshot opaque box overllaping

ASS

[Script Info]
ScriptType: v4.00+
PlayResX: 384
PlayResY: 288
ScaledBorderAndShadow: yes
YCbCr Matrix: None
WrapStyle: 0
Collisions: Reverse

[V4+ Styles]
Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
Style: Title,Pretendard ExtraBold,28,&H00ffffff,&H00ffffff,&H00000000,&H00000000,0,0,0,0,100,100,,,1,0.5,1.0,2,10,10,118,
Style: Subtitle,Pretendard ExtraBold,22,&H00ffffff,&H00ffffff,&H00000000,&Hff000000,0,0,0,0,100,100,,,1,,,2,10,10,40,
Style: Subtitle-box,Pretendard ExtraBold,22,&Hb3000000,&Hb3000000,&Hb3000000,&Hff000000,0,0,0,0,100,100,,,3,1.7,,2,10,10,40,

[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 11,0:00:53.91,0:00:56.91,Title,,0,0,0,,{\blur10}흥미진진한 뱀파이어 이야기
Dialogue: 1,0:00:53.91,0:01:06.45,Subtitle,,0,0,0,,{\blur0}진짜 {\blur0}신났네 {\blur0}신났네 {\blur0}목이 {\blur0}벌렸어요 {\blur0}나 {\blur0}아직 {\blur0}한 {\blur0}번도 {\blur0}안 {\blur0}벌렸어 {\blur0}잠시만요 {\blur0}뱀파이어로서 {\blur0}싱가포르 {\blur0}보기한테 {\blur0}뱀파이어로서
Dialogue: 0,0:00:53.91,0:01:06.45,Subtitle-box,,0,0,0,,진짜 신났네 신났네 목이 벌렸어요 나 아직 한 번도 안 벌렸어 잠시만요 뱀파이어로서 싱가포르 보기한테 뱀파이어로서

ThaUnknown / jassub

Prevent overlapped areas between opaque boxes from darkening #48