\breve{ A}_{\mu}  = -\frac{1}{2}\breve{ n}_k F_{\mu\nu}x_\nu, \, \tilde F_{\mu\nu}=\pm F_{\mu\nu}\end{aligned}$$ where the matrix $\breve{n}_k$ belongs to the Cartan subalgebra of $su(3)$ $$\begin{aligned}
 \breve n_k &=& T^3\ \cos\left(\xi_k\right) + T^8\ \sin\left(\xi_k\right),
\nonumber\\
\xi_k&=&\frac{2k+1}{6}\pi, \, k=0,1,\dots,5.
\label{HLxik}\end{aligned}$$ The values $\xi_k$ correspond to the boundaries of the Weyl chambers in the root space of $su(3)$. The minima are connected by the discrete parity and Weyl transformations, which indicates that the system is prone to existence of solitons (in real space-time) and kink configurations (in Euclidean space). Below we shall concentrate on the simplest configuration – kink interpolating between self-dual and anti-self-dual Abelian vacua. If the angle $\omega$ between chromoelectric and chromomagnetic fields is allowed to deviate from the constant vacuum value and all other parameters are fixed to the vacuum values, then the Lagrangian takes the form $$\begin{aligned}
\label{SG}
\mathcal{L}_{\textrm{eff}} &=& -\frac{1 }{2}\Lambda^2 b_{\textrm{vac}}^2 \partial_\mu \omega \partial_\mu \omega 
\\
&-& b_{\textrm{vac}}^4  \Lambda^4 \left(C_2+3C_3b_{\textrm{vac}}^2 \right){\sin^2\omega},\end{aligned}$$ with the corresponding sine-Gordon equation $$\begin{aligned}
    \partial^2\omega = m_\omega^2 \sin 2\omega,\ \   m_\omega^2 = b_{\textrm{vac}}^2  \Lambda^2\left(C_2+3C_3b_{\textrm{vac}}^2 \right),\end{aligned}$$ and the standard kink solution $$\omega(x_\mu) = 2\ {\rm arctg} \left(\exp(\mu x_\mu)\right)
\label{sakink}$$ interpolating between $0$ and $\pi$. Here $x_\mu$ stays for one of the four Euclidean coordinates. The kink describes a 