diff --git a/syntax/asm.nanorc b/syntax/asm.nanorc
index e01fe2bb..d85226c6 100644
--- a/syntax/asm.nanorc
+++ b/syntax/asm.nanorc
@@ -8,7 +8,7 @@ color red "\<[A-Z_]{2,}\>"
 color brightgreen "\.(data|subsection|text)"
 color green "\.(align|file|globl|global|hidden|section|size|type|weak)"
 color brightyellow "\.(ascii|asciz|byte|double|float|hword|int|long|short|single|struct|word)"
-icolor brightred "^[[:space:]]*[.0-9A-Z_]*:"
+color brightred "^[[:space:]]*[.0-9A-Za-z_]*:"
 color brightcyan "^[[:space:]]*#[[:space:]]*(define|undef|include|ifn?def|endif|elif|else|if|warning|error)"
 
 # Strings.
diff --git a/syntax/awk.nanorc b/syntax/awk.nanorc
index 20d76db0..1e4569ec 100644
--- a/syntax/awk.nanorc
+++ b/syntax/awk.nanorc
@@ -6,7 +6,7 @@ magic "awk script"
 comment "#"
 
 # Records.
-icolor brightred "\$[0-9A-Z_!@#$*?-]+"
+color brightred "\$[0-9A-Za-z_!@#$*?-]+"
 # Awk-set variables.
 color red "\<(ARGC|ARGIND|ARGV|BINMODE|CONVFMT|ENVIRON|ERRNO|FIELDWIDTHS)\>"
 color red "\<(FILENAME|FNR|FS|IGNORECASE|LINT|NF|NR|OFMT|OFS|ORS)\>"
diff --git a/syntax/cmake.nanorc b/syntax/cmake.nanorc
index a89a93de..acdf87f8 100644
--- a/syntax/cmake.nanorc
+++ b/syntax/cmake.nanorc
@@ -3,7 +3,7 @@
 syntax cmake "(CMakeLists\.txt|\.cmake)$"
 comment "#"
 
-icolor green "^[[:space:]]*[A-Z0-9_]+"
+color green "^[[:space:]]*[0-9A-Za-z_]+"
 icolor brightyellow "^[[:space:]]*(include|include_directories|include_external_msproject)\>"
 
 icolor brightgreen "^[[:space:]]*((else|end)?if|else|(end)?while|(end)?foreach|break)\>"
@@ -12,7 +12,7 @@ color brightgreen "[[:space:]](OR|AND|IS_NEWER_THAN|MATCHES|(STR|VERSION_)?(LESS
 
 icolor brightred "^[[:space:]]*((end)?(function|macro)|return)"
 
-icolor cyan start="\$(\{|ENV\{)" end="\}"
+icolor cyan start="\$(ENV)?\{" end="\}"
 color magenta "\<(APPLE|UNIX|WIN32|CYGWIN|BORLAND|MINGW|MSVC(_IDE|60|71|80|90)?)\>"
 
 color brightblue "(^|[[:space:]])#.*"
diff --git a/syntax/fortran.nanorc b/syntax/fortran.nanorc
index 499f95b3..fb2ff0b9 100644
--- a/syntax/fortran.nanorc
+++ b/syntax/fortran.nanorc
@@ -34,7 +34,7 @@ icolor yellow "\<(.or.|repeat|select case|then|where|while)\>"
 icolor magenta "\<(continue|cycle|exit|go?to|result|return)\>"
 
 # Strings.
-icolor yellow "<[^= 	]*>" ""(\\.|[^"])*""
+color yellow "<[^= 	]*>" ""(\\.|[^"])*""
 
 # Comments.
-icolor blue "!.*"
+color blue "!.*"
diff --git a/syntax/lua.nanorc b/syntax/lua.nanorc
index 79685090..7c66a52c 100644
--- a/syntax/lua.nanorc
+++ b/syntax/lua.nanorc
@@ -44,7 +44,7 @@ color brightmagenta "\<(false|nil|true)\>"
 
 # Decimal and hexadecimal numbers
 color red "\<[0-9]+(\.[0-9]*)?([Ee][+-]?[0-9]+)?\>"
-icolor red "\<0x[0-9a-f]+(\.[0-9a-f]*)?(p[+-]?[0-9]+)?\>"
+color red "\<0x[0-9A-Fa-f]+(\.[0-9A-Fa-f]*)?([Pp][+-]?[0-9]+)?\>"
 
 # Brackets
 color brightmagenta "\(|\)|\[|\]|\{|\}"
diff --git a/syntax/mgp.nanorc b/syntax/mgp.nanorc
index 7a6324f6..20503d20 100644
--- a/syntax/mgp.nanorc
+++ b/syntax/mgp.nanorc
@@ -4,6 +4,6 @@ syntax mgp "\.mgp$"
 header "^%include.*"
 comment "#"
 
-icolor green "^%[a-z].*"
+color green "^%[A-Za-z].*"
 color cyan "(^|[[:space:]])(#|%%).*"
 color ,green "[[:space:]]+$"
diff --git a/syntax/python.nanorc b/syntax/python.nanorc
index 0c60bb76..bc6b84fd 100644
--- a/syntax/python.nanorc
+++ b/syntax/python.nanorc
@@ -7,7 +7,7 @@ linter pyflakes
 comment "#"
 
 # Function definitions.
-icolor brightblue "def [0-9A-Z_]+"
+color brightblue "def [0-9A-Za-z_]+"
 # Keywords.
 color brightcyan "\<(and|as|assert|async|await|break|class|continue)\>"
 color brightcyan "\<(def|del|elif|else|except|finally|for|from)\>"
diff --git a/syntax/ruby.nanorc b/syntax/ruby.nanorc
index a840af02..c3317238 100644
--- a/syntax/ruby.nanorc
+++ b/syntax/ruby.nanorc
@@ -12,7 +12,7 @@ color yellow "\<(next|nil|not|or|redo|rescue|retry|return|self|super|then|true|u
 # Constants.
 color brightblue "(\$|@|@@)?\<[A-Z]+[0-9A-Z_a-z]*"
 # Ruby "symbols".
-icolor magenta "([ 	]|^):[0-9A-Z_]+\>"
+color magenta "([ 	]|^):[0-9A-Za-z_]+\>"
 # Some unique things we want to stand out.
 color brightyellow "\<(__FILE__|__LINE__)\>"
 # Regular expressions.
diff --git a/syntax/tex.nanorc b/syntax/tex.nanorc
index 2f483384..4ddec06f 100644
--- a/syntax/tex.nanorc
+++ b/syntax/tex.nanorc
@@ -5,6 +5,6 @@ magic "(La)?TeX document"
 linter chktex -v0 -q -I
 comment "%"
 
-icolor green "\\.|\\[A-Z]*"
+color green "\\.|\\[A-Za-z]*"
 color magenta "[{}]"
 color blue "(^|[^\])%.*"