diff --git a/collects/drracket/private/colored-errors.rkt b/collects/drracket/private/colored-errors.rkt
new file mode 100755
index 0000000000..c15ceae61a
--- /dev/null
+++ b/collects/drracket/private/colored-errors.rkt
@@ -0,0 +1,216 @@
+#lang racket
+
+(require unstable/contract)
+
+(struct msg-fragment:str (str) #:transparent)
+(struct msg-fragment:v (v) #:transparent)
+(struct colored-msg-fragment (locs frags important color) #:transparent)
+(define (msg-fragment? v) (or (msg-fragment:str v) (msg-fragment:v v) (colored-msg-fragment v)))
+
+(define srcloc-syntax/c (rename-contract (or/c srcloc? syntax? (listof (or/c srcloc? syntax?))) 'srcloc-syntax/c))
+
+(struct colored-error-message (fragments additional-highlights) #:transparent)
+(provide/contract [struct colored-error-message
+                          ([fragments (listof msg-fragment?)]
+                           [additional-highlights srcloc-syntax/c])]
+                  [struct msg-fragment:str ([str string?])]
+                  [struct msg-fragment:v ([v any/c])]
+                  [struct colored-msg-fragment ([locs srcloc-syntax/c]
+                                                [frags (listof (or/c msg-fragment:str? msg-fragment:v?))]
+                                                [important boolean?]
+                                                [color (or/c #f symbol?)])])
+
+(define-values (prop:exn:colored-message
+                exn:colored-message?
+                exn:colored-message-accessor)
+  (make-struct-type-property
+   'colored-message
+   (lambda (v str-info)
+     (contract (exn? . -> . colored-error-message?) v
+               'struct-definition 'color-error-accessor))))
+
+(provide/contract [get-error-messages/color (exn? . -> . colored-error-message?)])
+(define (get-error-messages/color exn)
+  (cond [(exn:colored-message? exn) ((exn:colored-message-accessor exn) exn)]
+        [(exn:srclocs? exn)
+         (colored-error-message (list (msg-fragment:str (exn-message exn)))
+                                ((exn:srclocs-accessor exn) exn))]
+        [else
+         (colored-error-message (list (msg-fragment:str (exn-message exn))) empty)]))
+
+(require gmarceau/test gmarceau/cut gmarceau/list gmarceau/contract gmarceau/util parser-tools/lex
+         (prefix-in : parser-tools/lex-sre)
+         (only-in srfi/1 break)
+         unstable/function)
+
+
+
+
+(define lex (lexer
+             [(eof) empty]
+             ["~|" (cons 'TildaPipe (lex input-port))]
+             ["|~" (cons 'PipeTilda (lex input-port))]
+             ["~v" (cons 'TildaV (lex input-port))]
+             [(:or any-char "~~")
+              (begin
+                (define rst (lex input-port))
+                (match rst
+                  [(list (? string? str) tail ...)
+                   (cons (string-append lexeme str) tail)]
+                  [_ (cons lexeme rst)]))]))
+
+(test 'lex (check-equal? (lex (open-input-string "~~foo ~| ~~| bar ~v|~ foo ~ "))
+                         '("~~foo " TildaPipe " ~~| bar " TildaV PipeTilda " foo ~ ")))
+
+(define (check-tildas-are-paired parsed)
+  (let loop ([tildas (filter (// match? <> (or 'TildaPipe 'PipeTilda)) parsed)] [i 1])
+    (match tildas
+      [(list) (void)]
+      [(list 'PipeTilda rst ...)
+       (error 'colored-format "The ~ath tilda-pipe is an unexpected close" i)]
+      [(list one) (error 'colored-format "There is an dangling ~a" one)]
+      [(list 'TildaPipe 'TildaPipe rst ...)
+       (error 'colored-format "The ~ath tilda-pipe is an unexpected open" (add1 i))]
+      [(list 'TildaPipe 'PipeTilda rst ...)
+       (loop rst (+ 2 i))])))
+
+(test 'check-tildas-are-paired
+      (define (go str) (check-tildas-are-paired (lex (open-input-string str))))
+      (check-exn-msg exn:fail? "dangling" (lambda () (go "~| |~ ~|")))
+      (check-exn-msg exn:fail? #rx"3.*close" (lambda () (go "~| |~ |~ |~")))
+      (check-exn-msg exn:fail? #rx"6.*open" (lambda () (go "~| |~ ~| |~ ~| ~|")))
+      (check-exn-msg exn:fail? #rx"2.*open" (lambda () (go "~| ~| |~ |~")))
+      (check-exn-msg exn:fail? #rx"3.*close" (lambda () (go "~| ~~| |~ |~"))))
+
+(define (count-tildas fmt)
+  (- (length (regexp-match* #rx"~" fmt))
+     (* 2 (length (regexp-match* #rx"~~" fmt)))))
+
+(define (check-arg who args n)
+  (when (< (length args) n)
+    (error 'colored-error-message "Missing arguments for ~a" who)))
+
+(define (colored-format:v args)
+  (check-arg "~v" args 1)
+  (values (msg-fragment:v (first args))
+          (rest args)))
+
+(define (colored-format:str fmt args)
+  (define n (count-tildas fmt))
+  (check-arg fmt args n)
+  (values (msg-fragment:str (apply format fmt (take args n)))
+          (drop args n)))
+
+(define (colored-format:str-or-v fmt-or-v args)
+  (if (eq? fmt-or-v 'TildaV)
+      (colored-format:v args)
+      (colored-format:str fmt-or-v args)))
+
+(define (colored-format:TildaPipe fragments args)
+  (check-arg "~|" args 1)
+  (define-values (sub rest-args)
+    (let loop ([fragments fragments] [args (rest args)])
+      (if (empty? fragments)
+          (values empty args)
+          (let ()
+            (define-values (f rest-args) (colored-format:str-or-v (first fragments) args))
+            (define-values (rest-fs rest-rest-args) (loop (rest fragments) rest-args))
+            (values (cons f rest-fs) rest-rest-args)))))
+  (define the-arg (first args))
+  (match the-arg
+    [(list loc imp col other ..1)
+     (error 'colored-format "Extraneous arguments to TildaPipe: ~a" other)]
+    [_ (void)])
+  
+  (contract (or/c srcloc-syntax/c
+                  (list/c srcloc-syntax/c boolean?)
+                  (list/c srcloc-syntax/c symbol?)
+                  (list/c srcloc-syntax/c boolean? symbol?)
+                  (list/c srcloc-syntax/c symbol? boolean?))
+            the-arg 'caller 'TildaPipe)
+  
+  (define is-important (and (list? the-arg) (findf (// eq? <> #t) the-arg)))
+  (define color (and (list? the-arg) (findf symbol? the-arg)))
+  (values (colored-msg-fragment (if (list? the-arg) (first the-arg) the-arg) sub is-important color) rest-args))
+
+(provide/contract [colored-format (([fmt string?]) (#:additional-highlights [additional-highlights srcloc-syntax/c]) #:rest [_ any/c]
+                                                   . ->i . [_ colored-error-message?])])
+(define (colored-format fmt #:additional-highlights [additional-highlights empty] . args)
+  (define parsed (lex (open-input-string fmt)))
+  
+  (check-tildas-are-paired parsed)
+  
+  (define fragments
+    (let loop ([parsed parsed] [args args])
+      (match parsed
+        [(list) (unless (empty? args)
+                  (error 'colored-format "There are ~a unused arguments" (length args)))
+                empty]
+        [(list 'TildaPipe tail ...)
+         (define-values (left right) (break (// match? <> 'PipeTilda) tail))
+         (define-values (result rest-args) (colored-format:TildaPipe left args))
+         (cons result (loop (rest right) rest-args))]
+        [(list f tail ...)
+         (define-values (result rest-args) (colored-format:str-or-v f args))
+         (cons result (loop tail rest-args))])))
+  
+  (colored-error-message fragments additional-highlights))
+
+(test 'colored-format
+      (check-equal? (colored-format "  ") (colored-error-message (list (msg-fragment:str "  ")) empty))
+      (check-equal? (colored-format "--~a--" 5)
+                    (colored-error-message (list (msg-fragment:str "--5--")) empty))
+      (check-match (colored-format "~|--~a--|~ foo" #'here 5)
+                   (colored-error-message (list (colored-msg-fragment (app syntax-e 'here) (list (msg-fragment:str "--5--")) #f #f) (msg-fragment:str " foo")) empty))
+      
+      (check-match (colored-format "~|--~a--~v--~a--|~ foo ~v bar ~||~ ~a" #'first 1 "inserted" 2 'inserted-too (list #'second 'red) 3 #:additional-highlights '(a b))
+                   (colored-error-message (list (colored-msg-fragment
+                                                 (app syntax-e 'first)
+                                                 (list (msg-fragment:str "--1--")
+                                                       (msg-fragment:v "inserted")
+                                                       (msg-fragment:str "--2--")) #f #f)
+                                                (msg-fragment:str " foo ")
+                                                (msg-fragment:v 'inserted-too)
+                                                (msg-fragment:str " bar ")
+                                                (colored-msg-fragment (app syntax-e 'second) empty #f 'red)
+                                                (msg-fragment:str " 3"))
+                                          '(a b)))
+      (check-match (colored-format " ~~ ~a ~a ~a ~a ~||~~~|" 1 2 3 4 #'here)
+                   (colored-error-message (list (msg-fragment:str " ~ 1 2 3 4 ")
+                                                (colored-msg-fragment (app syntax-e 'here) empty #f #f)
+                                                (msg-fragment:str "~|")) empty))
+      (check-exn-msg exn:fail? #rx"2.*unused" (lambda () (colored-format " ~a " 1 2 3))))
+
+(define (uncolor-message msg)
+  (let loop ([f (colored-error-message-fragments msg)])
+    (match f
+      [(msg-fragment:str str) str]
+      [(msg-fragment:v v) (format "~a" v)]
+      [(colored-msg-fragment locs frags imp col)
+       (string-append* (map loop frags))])))
+
+(define (important-srclocs msg)
+  (flatten
+   (filter-map (// match <> [(colored-msg-fragment locs _ #t _) locs] [_ #f])
+               (colored-error-message-fragments msg))
+   (colored-error-message-additional-highlights msg)))
+
+(struct exn:fail:colored:syntax exn:fail:syntax (colored-message)
+        #:transparent
+        #:property prop:exn:colored-message (lambda (v)
+                                              (define vec (struct->vector v))
+                                              (vector-ref vec (sub1 (vector-length vec)))))
+
+(define (raise-colored-syntax-error fmt #:additional-highlights [additional-highlights empty] . args)
+  (define formatted (apply colored-format fmt #:additional-highlights [additional-highlights empty] args))
+  (raise (exn:fail:colored:syntax (uncolor-message formatted)
+                                  (current-continuation-marks)
+                                  (important-srclocs formatted)
+                                  formatted)))
+
+
+
+
+(test 'get-error-messages/color
+      (check-equal? (get-error-messages/color (exn:fail:colored:syntax "ah!" (current-continuation-marks) (list #'here) (colored-error-message 1 2)))
+                    (colored-error-message 1 2)))