A note concerning the Grundy and ${\rm b}$-chromatic number of graphs

The Grundy number of a graph $G$ is the maximum number of colors used by the First-Fit coloring of $G$ and is denoted by $\Gamma(G)$. Similarly, the ${\rm b}$-chromatic number ${\rm{b}}(G)$ of $G$ expresses the worst case behavior of another well-known coloring procedure i.e. color-dominating coloring of $G$. We obtain some families of graphs $\mathcal{F}$ for which there exists a function $f(x)$ such that $\Gamma(G)\leq f({\rm{b}}(G))$, for each graph $G$ from the family. Call any such family $(\Gamma,b)$-bounded family. We conjecture that the family of ${\rm b}$-monotone graphs is $(\Gamma,b)$-bounded and validate the conjecture for some families of graphs.