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A graph is 1-planar if it can be drawn in the Euclidean plane so that each edge is crossed by at most one other edge. A 1-planar graph on $n$ vertices is optimal if it has $4n-8$ edges. We prove that 1-planar graphs with girth at least 6 are (1,1,1,1)-colorable (in the sense that each of the four color classes induces a subgraph of maximum degree one). Inspired by the decomposition of 1-planar graphs, we conjecture that every 1-planar graph is (2,2,2,0,0)-colorable.

A graph $G=(V,E)$ is called improperly $(d_1,\cdots ,d_k)$-colorable if the vertex set $V$ can be partitioned into subsets $V_1,\cdots ,V_k$ such that the graph $G\left[V_i\right]$ induced by the vertices of $V_i$ has maximum degree at most $d_i$ for all $1\le i\le k$. In this paper, we mainly study the improper coloring of $1$-planar graphs and show that $1$-planar graphs with girth at least $7$ are $(2,0,0,0)$-colorable.