My Coincidence encounter with $3$ , $4$ , $5$ and $6$

$\begin{aligned}{\color{#3D99F6}66\times66} & = {\color{#D61F06}4}3{\color{#D61F06}5}6\\ {\color{#3D99F6}666\times666} & = {\color{#D61F06}44}3{\color{#D61F06}55}6 \\{\color{#3D99F6}6666\times6666} & = {\color{#D61F06}444}3{\color{#D61F06}555}6 \\{\color{#3D99F6}66666\times66666}& = {\color{#D61F06}4444}3{\color{#D61F06}5555}6 \end{aligned}$

In the above multiplications it is observed that increasing the numbers of ${\color{#3D99F6}6}$ at different place values also the numbers of ${\color{#D61F06}4}$ and ${\color{#D61F06}5}$ increases less by $1$ . Are the above such multiplications always true ?